Plant Physiol. Biochem. [JOURNAL]
Sun
200 papers
Exogenous boron induced cell expansion and carbohydrate allocation, conferring leaf succulence and salt resistance in sugar beet.
Chowdhury MSN, Sagervanshi A, Hossain MS … +1 more , Mühling KH
Plant Physiol Biochem · 2026 Jun · PMID 42296578 · Publisher ↗
Boron is imperative for cell division and expansion. Salinity reduces transpiration, thereby inhibiting xylem-dependent boron (B) uptake and leaf growth. Increasing salinity, boron, and abscisic acid (ABA) levels act syn...
Boron is imperative for cell division and expansion. Salinity reduces transpiration, thereby inhibiting xylem-dependent boron (B) uptake and leaf growth. Increasing salinity, boron, and abscisic acid (ABA) levels act synergistically to affect water balance in plants. However, exogenous ABA enhances salt stress resistance in many plants. To date, the links between boron-mediated improvements in water relations and leaf succulence in salt-grown sugar beet remain elusive. Therefore, we elucidated the transcriptional expression of membrane ion transporters and cell wall expansion genes, as well as osmotic metabolites and ionic homeostasis, in response to exogenous boron under NaCl stress. Findings indicated that exogenous boron (EB) promoted leaf expansion alongside exogenous ABA (EA) in salt-grown sugar beet. This was substantially increased by boron (B) translocation and sucrose accumulation, together with upregulation of sucrose synthesis and transport genes (BvSPS1 and BvSUT1). Consequently, reduced Na translocation and improved Na/K homeostasis were accompanied by downregulation of ABA biosynthesis genes BvNCED2 and BvZEP in the leaves. This was associated with lower Na influx and increased expression of BvNHX8, BvSOS1 and BvHKT1;3 in the roots. Further, water balance and leaf ion transport are facilitated by upregulation of the membrane ion transporters BvPIP1;1, BvPIP2;2, BvNIP5;1 and BvHKT1;3, as well as by expression of the plasma membrane H-ATPase BvPM4. This aligns with increased mRNA levels of cell wall-loosening and expansion candidates, expansins (BvEXPA12 and BvEXP26), and xyloglucan endotransglucosylases (BvXET8 and BvXET22). Altogether, exogenous boron confers leaf succulence, as does exogenous ABA, and promotes salt resistance in sugar beet leaves.
A comparative transcriptome analysis of freezing stress responses in early-maturing rapeseed (Brassica napus L.) seedlings.
Yang B, Wang Q, Chen H … +8 more , Chen X, Xia X, Zhou Z, Sun L, Qian L, Liu Z, He X, Xiong X
Plant Physiol Biochem · 2026 Jun · PMID 42296577 · Publisher ↗
Rapeseed (Brassica napus L.) is one of most vital oil crops in China, and its cultivation in southern regions is crucial for national edible oil security. However, delayed sowing in southern rice-rapeseed rotation system...
Rapeseed (Brassica napus L.) is one of most vital oil crops in China, and its cultivation in southern regions is crucial for national edible oil security. However, delayed sowing in southern rice-rapeseed rotation systems exposes seedlings to subzero freezing events, which can cause severe foliar wilting, root injury, and mortality, thereby limiting overwintering survival and yield potential. To address this challenge, enhancing varietal cold tolerance is essential. This study evaluated two early-maturing rapeseed germplasms YLS145 (cold-sensitive) and YLS449 (cold-tolerant) under -4°C freezing treatment for 5 h at the three-leaf stage. The survival rate of the cold-tolerant germplasm YLS449 was significantly higher than that of the cold-sensitive germplasm YLS145, attributable to the rapid response of its antioxidant system. Transcriptome analysis indicated that freezing stress primarily impairs rapeseed physiology by disrupting the photosynthetic system and redox homeostasis. The YLS449 likely activates CBFs centered regulatory network through cold sensing, integrating Reactive Oxygen Species (ROS), circadian, calcium, and hormone signals (jasmonic acid (JA) and abscisic acid (ABA)) into a complex signaling network that enhances freezing tolerance. These findings establish a molecular foundation for cold adaptation mechanisms in early-maturing B. napus.
Overexpression of the sugar transporter VvHT5 in grapevine drives coordinated host-pathogen transcriptional reprogramming favoring Botrytis cinerea.
Monnereau B, Cuello C, Gaillard C … +5 more , Lebeurre V, Videau P, Zekri O, Coutos-Thévenot P, La Camera S
Plant Physiol Biochem · 2026 Jun · PMID 42287978 · Publisher ↗
Sugars are key modulators of plant-pathogen interactions, serving both as metabolic resources and as signaling molecules that influence defense outcomes. In grapevine (Vitis vinifera L.), the hexose transporter VvHT5, an...
Sugars are key modulators of plant-pathogen interactions, serving both as metabolic resources and as signaling molecules that influence defense outcomes. In grapevine (Vitis vinifera L.), the hexose transporter VvHT5, an ortholog of Arabidopsis thaliana STP13, is strongly induced during fungal infections, suggesting a role in host-pathogen interaction-related sugar partitioning. Here, we examined the function of VvHT5 in grapevine susceptibility to the necrotrophic fungus Botrytis cinerea. Transgenic lines overexpressing VvHT5 were generated in two cultivars, Thompson Seedless and Chardonnay, and displayed increased sugar uptake in leaves. Upon B. cinerea inoculation, these lines exhibited enhanced lesion development and fungal proliferation, contrasting with the tolerance phenotype previously observed in A. thaliana expressing VvHT5. Dual RNAseq analysis revealed that VvHT5 overexpression triggers a transcriptional landscape favoring carbohydrate metabolism, cell wall remodeling, and attenuation of defense responses, paralleled by upregulation of fungal genes involved in sugar acquisition and virulence. These results demonstrate that while VvHT5 contributes to restricting sugar availability to pathogens in A. thaliana, its constitutive activation in grapevine enhances host suitability for B. cinerea. Our findings highlight the complexity of sugar-mediated interactions and underscore the importance of host context in determining the outcome of plant-pathogen competition for carbon resources.
The pentose phosphate pathway coordinates cytokinin homeostasis and CpG island methylation to control radicle development in maize.
Zhang Z, Li Z, Wang K … +10 more , Zhang Y, Wang S, Teng H, Wu L, Wang Y, Jiao F, Zhang H, Sakr S, Chen J, Wang M
Plant Physiol Biochem · 2026 Jun · PMID 42287977 · Publisher ↗
The pentose phosphate pathway (PPP) is a crucial metabolic route that influences various physiological processes in plants. In this study, we examined the effects of PPP inhibition on maize radicle growth using the PPP i...
The pentose phosphate pathway (PPP) is a crucial metabolic route that influences various physiological processes in plants. In this study, we examined the effects of PPP inhibition on maize radicle growth using the PPP inhibitors and mutant. Our results showed that PPP inhibition significantly reduces radicle length, accompanied by a substantial decrease of energy level. Furthermore, molecular analyses revealed that PPP inhibition downregulates the cytokinin biosynthesis gene IPT while upregulating cytokinin oxidase/dehydrogenase (CKX) protein abundance. Bioinformatic and biochemical investigations identified a flavin adenine dinucleotide (FAD)-binding domain in CKX and showed that PPP blockade reduces root FAD content, impairing CKX enzymatic activity. Transcriptomic and metabolomics analysis revealed that PPP inhibition downregulates ZmRR3, a cytokinin signaling related response regulator, through DNA methylation in its promoter region. Notably, DNA methylation inhibition via 5-Azacytidine treatment restores radicle growth and ZmRR3 expression. These findings highlight the essential role of PPP in regulating energy metabolism, cytokinin content, and gene expression during maize radicle development. This study advances understanding of the metabolic-cytokinin interplay critical for radicle growth and offers potential molecular targets for maize improvement.
Corrigendum to "Detailed characterization of ovule and seed development in Camelina sativa reveals a conserved DELLA GAI pathway for seed size" [Plant Physiol. Biochem. 233 (2026), 1-11 111228].
Sánchez-Matilla J, Frontela I, Tornero P … +2 more , Perez-Amador MA, Gomez MD
Plant Physiol Biochem · 2026 Jul · PMID 42285805 · Publisher ↗
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Pseudomonas fragi Sneb1990 flagellin flg22 stimulates solavetivone synthesis pathway to enhance tomato plants against Meloidogyne incognita.
Lu X, Zhao S, Yang L … +7 more , Gan Y, Tang M, Hu Z, Li D, Sun R, Wang S, Chen L
Plant Physiol Biochem · 2026 Jun · PMID 42284718 · Publisher ↗
Bacterial flagellin (flg), a key MAMP, activates plant immunity against various diseases. Solavetivone is a major sesquiterpenoid phytoalexin that forms one layer of defense against fungi pathogens in Solanaceae plants....
Bacterial flagellin (flg), a key MAMP, activates plant immunity against various diseases. Solavetivone is a major sesquiterpenoid phytoalexin that forms one layer of defense against fungi pathogens in Solanaceae plants. However, the function of compound and biosynthetic pathway genes of solavetivone in Solanaceae plants against Meloidogyne incognita has not been explored. In this study, we discovered 49 differentially expressed genes through RNA-seq analysis of tomato plants treated with Pseudomonas fragi flagellin flg22 and M. incognita, among them two of the solavetivone synthesis genes, premnaspirodiene oxygenase (K15472) and vetispiradiene synthase (K14182) were found with function against M. incognita. Further subcellular localization indicated that K15472 is localized to the endoplasmic reticulum (ER) and cell membrane, whereas K14182 is localized to the nucleus, cell membrane, and ER. The contents of solavetivone in K14182 and K15472 over-expressing plants increased by 6.21 and 4.57 folds. Correspondingly, the number of nematodes in the roots of tomato plants with over-expression of these two genes was significantly lower than that in the roots of wild-type (WT) tomato plants. Subsequently, the Pluronic F-127 model demonstrated that solavetivone exhibited a concentration-dependent dual effect: a low concentration (0.01 mg/L) attracted M. incognita, and a high concentration (≥0.1 mg/L) repelled it. Furthermore, the external application of solavetivone at 5 mg/L and 10 mg/L led to a significant reduction of nematode infestation in potted plants. These results collectively verify that P. fragi flagellin flg22 triggers solavetivone synthesis to increase tomato plant resistance against M. incognita by stimulating the expression of K14182 and K15472 genes.
Unraveling the pleiotropic functions of Rhizobium rhizogenes rolB and rolC genes on phenotype, secondary metabolism, and drought tolerance in Atropa belladonna.
Liang S, Mu D, Ma Y … +8 more , Xu G, Shangguan L, Yang Z, Chen R, Zhang J, Ma B, Zhang M, Qiang W
Plant Physiol Biochem · 2026 May · PMID 42284717 · Publisher ↗
Atropa belladonna L. (Solanaceae) is a significant source of the pharmacologically important tropane alkaloids (TAs), particularly hyoscyamine and scopolamine. Although rolB and rolC from Rhizobium rhizogenes are known t...
Atropa belladonna L. (Solanaceae) is a significant source of the pharmacologically important tropane alkaloids (TAs), particularly hyoscyamine and scopolamine. Although rolB and rolC from Rhizobium rhizogenes are known to enhance plant secondary metabolism, their functional specificities and combined actions in TAs biosynthesis remain unclear. Here, we generated transgenic A. belladonna overexpressing 35S::rolB, 35S::rolC, and 35S::rolB + rolC to systematically investigate their effects on TAs accumulation, plant morphology, and drought tolerance. Co-expression of rolB and rolC exhibited metabolic antagonism, with TAs levels significantly lower than in rolC single transgenic plants, further establishing rolC as the primary regulator of this pathway. Phenotypic analysis revealed divergent effects: rolB increased leaf size and promoted root growth, whereas rolC caused dwarfism, early flowering, and male sterility; double transgenic plants displayed exacerbated growth inhibition. Notably, rolC-expressing plants showed improved drought performance via combined morphological and antioxidant adjustments. Mechanistically, both genes upregulated key biosynthetic genes, with rolC regulating a broader set. Protein interaction assays revealed that RolC directly interacts with TRI, calmodulin (CaM1/CaM7), and the brassinosteroid signaling component BSK. A root-specific transcription factor, AbbHLH30, was identified as a candidate downstream component of the RolC-CaM1 module, with the capacity to activate H6H expression in transient assays. This study provides a mechanistic basis for understanding rol gene functions and offers specific molecular targets for engineering TAs production in A. belladonna.
Pan-genome analysis of the P-type ATPase gene family in Prunus mume and functional characterization of PmAHA3 in organic acid accumulation.
Lin X, Guo S, Yang R … +10 more , Xu W, Cheng D, Wang Z, Li W, Segbo S, Zhou P, Huang X, Ni Z, Shi T, Gao Z
Plant Physiol Biochem · 2026 Jun · PMID 42284716 · Publisher ↗
Organic acid accumulation is a key determinant of fruit flavor and processing quality in Prunus mume, yet its underlying molecular mechanisms remain poorly understood. P-type ATPases are membrane proteins that drive the...
Organic acid accumulation is a key determinant of fruit flavor and processing quality in Prunus mume, yet its underlying molecular mechanisms remain poorly understood. P-type ATPases are membrane proteins that drive the active transport of ions and molecules via ATP hydrolysis and play important roles in organic acid accumulation However, their genome-wide features and functions in P. mume remain poorly understood. Here, 49 P-type ATPase genes were identified from the P. mume pan-genome, including 29 core, 6 near-core, 11 dispensable, and 3 private genes, and classified into six subfamilies. Dispersed and whole-genome duplication were the major force driving gene family expansion, and most genes experienced strong negative selection. Expression profiling identified the P3A-type gene PmAHA3 as highly expressed in fruit, with vacuolar membrane localization. Both transient RNAi silencing in fruit and CRISPR/Cas9 knockout in callus significantly reduced the contents of malic and citric acid, demonstrating their roles in organic acid accumulation. These results provide insight into the evolution and function of P-type ATPases, offering potential targets for improving fruit quality.
Deletion of Ph1 locus enhances low temperature tolerance via glucosamine metabolism rewiring in wheat.
Dai B, Wang B, Zhang P … +2 more , Haider FU, Li X
Plant Physiol Biochem · 2026 Jun · PMID 42284715 · Publisher ↗
Deletion of the Ph1 locus is known to disrupt chromosome pairing in wheat, but its role in environmental stress adaptation, particularly low temperature tolerance, remains unclear. Low temperature severely impairs wheat...
Deletion of the Ph1 locus is known to disrupt chromosome pairing in wheat, but its role in environmental stress adaptation, particularly low temperature tolerance, remains unclear. Low temperature severely impairs wheat productivity by inducing oxidative damage and disrupting photosynthesis. However, the mechanistic links between Ph1 deletion and low temperature tolerance are still poorly understood. This study aimed to investigate the physiological, transcriptomic, and metabolic effects of Ph1 deletion on wheat's response to low temperature stress. Using the ph1b-8 mutant derived from a low-temperature-screened ph1b population and the reference cultivar Chinese Spring, plants were subjected to controlled low temperature treatments (0/4°C, dark/light). Photosynthetic efficiency, membrane integrity, RNA-sequencing, and enzyme activity assays, which focused on glucosamine metabolism and antioxidant pathways, were performed to elucidate molecular adaptations. Transcriptomic profiling revealed DEGs enriched in glucosamine metabolism and photosynthetic pathways, particularly at low temperature, with significant upregulation of glucosamine-metabolizing enzymes (glutamine: fructose-6-phosphate amidotransferase, glucosamine-6-phosphate deaminase, and N-acetylglucosamine kinase) and upstream carbohydrate-processing enzymes (hexokinase), indicating increased flux toward UDP-GlcNAc biosynthesis and accelerated glucose flux. Additionally, the transcriptomic changes suggest a potential mechanism in which the enhanced glucosamine metabolic pathway may synergize with glutathione metabolism to mitigate oxidative damage. Collectively, these findings reveal a previously unrecognized metabolic and transcriptional reprogramming associated with low temperature tolerance in the ph1b-derived mutant line studied (ph1b-8). This selected mutant line provides new genetic resources and mechanistic insights for improving tolerance to stress conditions.
Constitutive zeaxanthin accumulation affects photosynthetic activity and non-photochemical quenching in Chlorella vulgaris.
Cazzaniga S, Martini F, Zenaro C … +3 more , Cuine S, Li-Beisson Y, Ballottari M
Plant Physiol Biochem · 2026 Jun · PMID 42284714 · Publisher ↗
Carotenoids play crucial roles in light harvesting and photoprotection in photosynthetic organisms, although their functions in non-model microalgae remain poorly understood. Here, we investigated the effects of constitu...
Carotenoids play crucial roles in light harvesting and photoprotection in photosynthetic organisms, although their functions in non-model microalgae remain poorly understood. Here, we investigated the effects of constitutive zeaxanthin accumulation in the green microalga Chlorella vulgaris. A mutant strain, named fm53 (fluorescence mutant 53), was isolated by UV mutagenesis and characterized by constitutive zeaxanthin accumulation together with the absence of other β-β xanthophylls. Whole-genome sequencing identified 36 single-nucleotide variants, including a mutation in the 5' untranslated region of the zeaxanthin epoxidase (ZEP) gene, associated with the absence of detectable ZEP protein accumulation. Compared with the wild type, fm53 accumulated higher levels of zeaxanthin, showed altered Photosystem II supercomplex organization, reduced maximum photosynthetic efficiency, and strongly decreased light-dependent non-photochemical quenching (NPQ). Fluorescence lifetime analysis revealed constitutive zeaxanthin-dependent quenching mechanisms in the mutant. Despite these alterations, biomass productivity remained similar to the wild type under most growth conditions tested. These results provide new insights into the roles of zeaxanthin and the xanthophyll cycle in regulating photosynthesis and photoprotection in C. vulgaris. Moreover, the constitutive accumulation of zeaxanthin highlights the potential of the fm53 strain as a source of high-value carotenoids.
Multi-omics insights into antioxidant defense, phenylpropanoid, and flavonoid pathways governing cold stress tolerance in cotton (Gossypium hirsutum).
Abro AA, Tabusam J, Abbas M … +9 more , Khalid S, Liu Q, Abbas K, Jie Z, Xu Y, Hou Y, Zhou Z, Cai X, Liu F
Plant Physiol Biochem · 2026 Jul · PMID 42275816 · Publisher ↗
Cold stress adversely affects cotton growth and development often causing morphological abnormalities during germination and seedling establishment. Nevertheless, the molecular and metabolic mechanisms conferring cold to...
Cold stress adversely affects cotton growth and development often causing morphological abnormalities during germination and seedling establishment. Nevertheless, the molecular and metabolic mechanisms conferring cold tolerance in cotton remain largely unclear. The study aimed to examine the morphological and physiological responses of two semi-wild Gossypium hirsutum accessions, the cold resistant Latifolium (CR-307) and cold susceptible Punctatum (CS-131) under cold stress. The experiment was conducted at two temperature regimes: 28-30 °C (control) and 4 °C for 96 h (cold stress). In comparison to the control, primary root length (PRL) decreased by 63% in CR-307 and by 73% in CS-131. Furthermore, biochemical analysis confirmed that CR-307 exhibited a stronger antioxidant defense system, showing higher SOD, POD, and CAT activities and reduced HO accumulation under cold stress compared with CS-131. Transcriptome analysis identified 3135 differentially expressed genes (DEGs) associated with cold response regulation, mainly belonging to MYB, AP2/ERF, bHLH, WRKY, bZIP, and HSF transcription factor families. Cold stress also altered pathways related to phenylpropanoid, proline, flavonoid, and cofactor biosynthesis, reflecting adaptive molecular reprogramming. Moreover, 328 lipids, 105 organic acids, 87 phenylpropanoids and 39 flavonoids were detected as differentially expressed metabolites (DEMs) that contribute to cell wall reinforcement, antioxidant defense, transcriptional regulation and membrane stabilization under cold stress. Overall, the study provides comprehensive insights into the molecular and metabolic mechanisms underlying cold tolerance in cotton, offering potential targets for developing cold-resilient cultivars.
Suaeda salsa strategically utilizes nitrate and ammonium nitrogen for salt tolerance.
Liu Q, Wang S, Zhao Z … +4 more , Zhang K, Wang Y, Mai W, Tian C
Plant Physiol Biochem · 2026 Jul · PMID 42275815 · Publisher ↗
Soil salinization is a major environmental constraint on plant growth. Although halophytes can grow well in saline soils, their nitrogen-use strategies under saline conditions remain poorly understood. In this study, the...
Soil salinization is a major environmental constraint on plant growth. Although halophytes can grow well in saline soils, their nitrogen-use strategies under saline conditions remain poorly understood. In this study, the typical euhalophyte Suaeda salsa was used as the study species to investigate how different salinity levels and nitrogen forms (nitrate-N, ammonium-N, and a nitrogen-free control) regulate its growth, physiological traits, nitrogen metabolism, osmotic adjustment, oxidative stress, and metabolomic responses. The results showed that S. salsa adopted distinct strategies for utilizing nitrate and ammonium under salt stress. Nitrate nutrition more strongly promoted biomass accumulation, shoot height, and root elongation, while also supporting nitrate accumulation as an inorganic osmoticum. Under high salinity, NO-N accounted for 62.11% of total nitrogen, and the osmotic contribution of nitrate reached -0.16 MPa. This nitrate-retention strategy was associated with enhanced antioxidant capacity, reduced oxidative damage, and the accumulation of metabolites related to jasmonate signaling, glutathione turnover, and phenylpropanoid metabolism. In contrast, ammonium nutrition favored tissue hydration, canopy width, and root thickening. More than 84% of total nitrogen was maintained in organic forms under NH-N supply, indicating efficient ammonium assimilation and detoxification. Metabolomic profiling further showed that ammonium treatment promoted the accumulation of nitrogen-rich osmotic and buffering metabolites, including arginine, histidine, and ornithine, particularly under high salinity. Overall, S. salsa exhibits dual nitrogen-use strategies, and this physiological and metabolic plasticity may contribute to its ecological success in saline environments.
An R2R3-MYB transcription factor NtMYB78 modulates growth and development in tobacco via the phenylpropanoid biosynthesis pathway.
Chen H, Chen N, Zhi B … +9 more , Zhang D, Chen Z, Lin J, Wang Z, Mao H, Pan D, Li J, Huang Z, Pan X
Plant Physiol Biochem · 2026 Jul · PMID 42275814 · Publisher ↗
MYB transcription factors are integral to plant growth and development. In this study, we aimed to elucidate the function of NtMYB78, an R2R3-type MYB transcription factor in tobacco (Nicotiana tabacum L.), by generating...
MYB transcription factors are integral to plant growth and development. In this study, we aimed to elucidate the function of NtMYB78, an R2R3-type MYB transcription factor in tobacco (Nicotiana tabacum L.), by generating overexpression (OE) and knockout (KO) lines. Through a combination of phenotypic characterization, transcriptomic analysis, and metabolomic profiling, we investigated the regulatory mechanisms by which NtMYB78 influences tobacco growth and development. The findings indicated that NtMYB78 was predominantly expressed in roots and was localized to the nucleus. The OE lines exhibited a marked increase in root length during both the seedling and mature stages. Additionally, these lines demonstrated significantly higher SPAD values, chlorophyll content, and photosynthetic rates during the seedling stage. Conversely, the KO lines manifested phenotypes that were diametrically opposed to those observed in the OE lines. Transcriptome analysis demonstrated that, in roots, the OE lines exhibited upregulation of genes associated with the motor protein pathway and downregulation of genes involved in the phenylpropanoid biosynthesis pathway. Conversely, the KO lines showed a marked downregulation of genes linked to motor protein and carbohydrate metabolism. In shoots, the OE lines upregulated genes involved in the phenylpropanoid biosynthesis and photosynthetic carbon fixation pathways, whereas the KO lines downregulated genes associated with photosynthesis-related pathways. Metabolomic analysis revealed a significant increase in spermine content within the roots of OE lines, potentially facilitating root elongation. Integrated analysis further demonstrated that NtMYB78 enhances "source-sink" resource allocation in tobacco by activating phenylpropanoid biosynthesis and carbon fixation pathways in shoots, while concurrently inhibiting phenylpropanoid synthesis in roots to reduce lignin deposition. This study elucidates the molecular mechanisms by which NtMYB78 modulates root growth and photosynthetic capacity in tobacco, offering a novel molecular target for the genetic improvement of tobacco.
PagWRKY40 transcription factor improved insect resistance of Populus alba ×P. glandulosa.
Chi Y, Sun Y, Peng D … +3 more , Chen W, Zhang X, Zhao X
Plant Physiol Biochem · 2026 Jul · PMID 42269266 · Publisher ↗
Forest pests and diseases exert serious impacts on the growth, development and yield of trees. In response to insect infestation, trees have evolved complex and interconnected regulatory pathways to induce plant defense...
Forest pests and diseases exert serious impacts on the growth, development and yield of trees. In response to insect infestation, trees have evolved complex and interconnected regulatory pathways to induce plant defense responses. Metabolites such as jasmonic acid (JA) and flavonoids play important roles in plants defense against insects. In this study, we found that a transcription factor of the WRKY IIa subgroup, PagWRKY40, is localized in the nucleus. Insect feeding assays indicated that the overexpression of the PagWRKY40 in 84K poplar (Populus alba×Populus glandulosa) could enhance the resistance to the fall webworm (Hyphantria cunea) by reducing the feeding amount, increasing the activities of catalase (CAT), lipoxygenase (LOX), polyphenol oxidase (PPO), and elevating the contents of JA and flavonoids. RNA-seq analysis indicated that the differentially expressed genes (DEGs) between PagWRKY40-overexpressing (PagWRKY40-OE) plants and wild-type (WT) plants were significantly enriched in oxidase activity and the biosynthetic pathways of metabolites such as phenylpropane and flavonoids. Moreover, PagWRKY40 can directly bind to the W-box elements on the PagLOX3, PagCHI and PagPAL3 promoters to regulate the biosynthesis of JA and flavonoids, thereby enhancing the resistance of 84K poplar to fall webworm. In conclusion, these results indicate that PagWRKY40 is a transcription factor that positively regulates plant insect resistance defense, which can provide candidate germplasm resources for the breeding of new insect-resistant forest tree varieties in the future and lay the foundation for elucidating the mechanisms of plant insect resistance defense.
The NLR splice variant BNT1.1 contributes to vascular defense responses affecting callose accumulation and Myzus persicae feeding in arabidopsis.
Peppino Margutti MY, Inostroza C, Zavala D … +7 more , Delgado-Rioseco J, Ramirez L, Cid C, Silva-Sanzana C, Herrera-Vásquez A, Cecchini NM, Blanco-Herrera F
Plant Physiol Biochem · 2026 Jul · PMID 42269265 · Publisher ↗
Aphids are phloem-feeding insects that probe through successive plant cell layers before establishing sustained feeding in sieve elements. During this process, they secrete salivary effectors that can modulate plant immu...
Aphids are phloem-feeding insects that probe through successive plant cell layers before establishing sustained feeding in sieve elements. During this process, they secrete salivary effectors that can modulate plant immune responses to facilitate access to vascular tissues. Although nucleotide-binding leucine-rich repeat receptors (NLRs) are central components of plant immunity against microbial pathogens, their role in plant-aphid interactions remains poorly understood. Here, we investigated the Arabidopsis TIR-type NLR BURNOUT1 (BNT1), which produces two transcriptional isoforms with distinct tissue distributions. Previous work showed that the plastid-localized isoform BNT1.2 accumulates mainly in epidermal tissues and contributes to antibacterial immunity, whereas the function of the vascular-enriched isoform BNT1.1 remains unknown. During infestation by the green peach aphid (Myzus persicae), BNT1 expression was transiently induced, with BNT1.1 accumulating markedly in vascular tissues while BNT1.2 remained enriched in epidermal fractions. Moreover, loss-of-function bnt1 mutants displayed increased aphid reproduction and prolonged phloem sap ingestion, as measured by electrical penetration graph recordings. These plants also showed reduced callose deposition in vascular tissues and lower expression of the phloem-associated callose synthase gene CALS7. Restoring BNT1.1 expression in the bnt1 background increased callose accumulation at aphid feeding sites and rescued the feeding phenotype. Overall, our results indicate that BNT1 plays a role in vascular defense responses that limit prolonged phloem feeding by aphids. Together, our findings reveal that alternative transcription of immune receptors contributes to spatially resolved defense responses in plants. This work highlights a mechanism linking molecular diversification to cell-type-specific immunity and provides new insight into how plants coordinate defense strategies against phloem-feeding insects.
XsMAX2 negatively regulates post-fertilization ovule development in Xanthoceras sorbifolium.
Zhou Q, Cai Q, Zhou L … +1 more , Liu J
Plant Physiol Biochem · 2026 Jul · PMID 42269264 · Publisher ↗
The Arabidopsis MAX2 gene encodes an F-box protein containing a leucine-rich repeat (LRR) domain, which plays a pivotal role in regulating plant development and stress responses. Although MAX2 has been extensively charac...
The Arabidopsis MAX2 gene encodes an F-box protein containing a leucine-rich repeat (LRR) domain, which plays a pivotal role in regulating plant development and stress responses. Although MAX2 has been extensively characterized in these processes, its specific function in post-fertilization ovule development remains elusive. Our previous work identified XsMAX2, a MAX2 homolog in Xanthoceras sorbifolium, as highly expressed in fertilized ovules. Here, we demonstrate that XsMAX2 is a nuclear-localized protein that interacts with SKP1, a core component of the SCF (SKP1-CUL1-F-box) ubiquitin ligase complex. Furthermore, we show that the auxin-responsive transcription factor ARF2 directly binds to the XsMAX2 promoter, regulating its expression in fertilized ovules. Functional studies reveal that upregulation of XsMAX2 leads to increased fruit and ovule abortion, whereas its downregulation enhances their growth and development. Notably, XsMAX2 expression is precisely modulated by nutrient availability (e.g., phosphate and sugars) and the phytohormone pathways (e.g. strigolactone and abscisic acid). Mechanistically, XsMAX2 may suppress cell cycle-related genes and induce aberrant programmed cell death (PCD) in post-fertilization ovules, thereby impairing early seed development. Collectively, our findings establish XsMAX2 as a critical negative regulator of post-fertilization ovule development in X. sorbifolium, integrating environmental and endogenous signals to control reproductive success.
ABA-cytokinin crosstalk regulate drought tolerance in Ziziphus jujuba var. spinosa through the phenylpropanoid pathway: insights from physiological and multi-omics integration.
Li M, Zhou S, Jiang M … +5 more , Geng J, Ni H, Li G, Zhao Y, Dong Y
Plant Physiol Biochem · 2026 Jul · PMID 42269263 · Publisher ↗
Drought stress is a major constraint in jujube production. Although abscisic acid (ABA) and cytokinin exert opposing effects on plant growth, recent findings revealed that their combined application enhanced drought tole...
Drought stress is a major constraint in jujube production. Although abscisic acid (ABA) and cytokinin exert opposing effects on plant growth, recent findings revealed that their combined application enhanced drought tolerance in jujube; however, the underlying mechanism remains elusive. In this study, three exogenous treatments were applied to sour jujube seedlings under drought stress: 5 mg L ABA, a cytokinin mixture of 50 mg L 6-benzylaminopurine (6-BA) and 100 mg L kinetin (KT), and a combined ABA and cytokinins solution. Transcriptomic and metabolomic analyses were integrated to elucidate how ABA and cytokinins jointly modulate drought responses. The results showed that ABA induced stem thickening, enhanced osmotic regulation and antioxidant capacity, upregulated the expression of cytochrome P450 84A1-like (CYP84A1) involved in lignin biosynthesis, and downregulated cinnamyl alcohol dehydrogenase (CAD). In contrast, cytokinins promoted stem elongation by upregulating elongation factor 2 and L-lactate dehydrogenase B, downregulating anthocyanin synthase (ANS) and peroxidase, and altering galactose/starch metabolism, thereby prioritizing growth at the expense of stress tolerance. The combined treatment reconciled these opposing effects, enhancing stress defense without compromising cytokinin-mediated growth advantage, inducing 3018 differential genes and 285 metabolites. The phenylpropanoid biosynthesis pathway was identified as central to ABA-cytokinin crosstalk, with upregulation of two CADs contributing to drought resistance and four genes encoding CAD, peroxidase, and cinnamate 4-hydroxylase (C4H) playing a critical role in this crosstalk. Additionally, beta-glucosidase 18 (BGLU18) was identified as a candidate gene correlated with 13 phenylpropanoids. Our findings reveal the molecular link between the phenylpropanoid pathway and ABA-cytokinin crosstalk in jujube drought tolerance.
Diallyl disulfide promotes root elongation through auxin biosynthesis involving the CsBBM2-CsYUC6 transcriptional regulation in cucumber.
Shi M, Xiao Q, Yang X … +3 more , Xian J, Wang H, Yang F
Plant Physiol Biochem · 2026 Jul · PMID 42263532 · Publisher ↗
Intercropping cucumber with garlic is an effective agronomic practice to mitigate soil sickness in continuous cropping systems. The garlic root exudate diallyl disulfide (DADS) promotes cucumber root elongation, though t...
Intercropping cucumber with garlic is an effective agronomic practice to mitigate soil sickness in continuous cropping systems. The garlic root exudate diallyl disulfide (DADS) promotes cucumber root elongation, though the molecular mechanism remains unknown. Here, we show that 1 mM DADS enhances cucumber primary root elongation by stimulating cell expansion. Hormone quantification combined with exogenous auxin application and pharmacological inhibition demonstrated that DADS-induced root elongation is auxin-dependent. Transcriptomic and weighted gene co-expression network analyses identified a key auxin biosynthetic gene, CsYUC6, which is up-regulated by DADS, and its upstream transcriptional regulator, CsBBM2. Electrophoretic mobility shift and dual-luciferase assays confirmed that CsBBM2 acts as a transcriptional repressor of CsYUC6 by directly binding to its promoter. Our results suggest that DADS promotes root growth by downregulating CsBBM2, a transcriptional repressor of the auxin biosynthesis gene CsYUC6, thereby increasing auxin levels in cucumber roots. The result provides mechanistic insight into cucumber-garlic intercropping and supports the potential use of DADS as a sustainable agrochemical.
Identification and functional analysis of GbMYB15 as a negative regulator in flavonoid biosynthesis of Ginkgo biloba.
Gao X, Geng W, Zhao Y … +6 more , Yang J, Liu H, Liu X, Zhang W, Xu F, Ye J
Plant Physiol Biochem · 2026 Jul · PMID 42263531 · Publisher ↗
Flavonoids, which possess diverse pharmacological properties, are abundant in Ginkgo biloba leaves and contribute to the prevention of cardiovascular and cerebrovascular diseases. R2R3-MYB transcription factors are cruci...
Flavonoids, which possess diverse pharmacological properties, are abundant in Ginkgo biloba leaves and contribute to the prevention of cardiovascular and cerebrovascular diseases. R2R3-MYB transcription factors are crucial regulators of flavonoid metabolism, yet their functions, particularly those involving negative regulation in G. biloba, remain poorly understood. In this study, GbMYB15, a gene implicated in flavonoid biosynthesis, was cloned based on preliminary transcriptome data. Its functional role was investigated through bioinformatics analysis, transient overexpression in G. biloba, and stable heterologous expression in Arabidopsis thaliana. The results showed that the GbMYB15 protein contains a C1 activation motif. Under exogenous ABA and MeJA treatments, the expression level of GbMYB15 was negatively correlated with the total flavonoid content. Overexpression of GbMYB15 in A. thaliana and G. biloba significantly reduced the total flavonoid content, confirming that GbMYB15 is a negative regulator of total flavonoid synthesis. Furthermore, yeast two-hybrid, bimolecular fluorescence complementation, and luciferase complementation imaging assays confirmed that GbMYB15 interacts with the energy metabolism-related protein Gb34759. Transient overexpression experiments in G. biloba leaves further showed that the interaction between GbMYB15 and Gb34759 enhances the negative regulatory capacity of GbMYB15. Dual-luciferase reporter assays indicated that GbDFR2 is a candidate downstream structural gene potentially regulated by GbMYB15 in flavonoid biosynthesis. Based on these results, this study hypothesizes a regulatory model: GbMYB15 may affect total flavonoid content by modulating the flux of the GbDFR2-associated pathway, and that the interaction between GbMYB15 and Gb34759 may enhance this regulatory effect. This work provides a theoretical foundation for future genetic engineering efforts aimed at enhancing flavonoid content in G. biloba.
Cold stratification releases epicotyl dormancy in Yunnanopilia longistaminea by rebalancing ABA-GA and remodeling cell-wall polysaccharides across seed tissues.
Yang G, Liu X, Zhang Q … +2 more , Han S, Wang Y
Plant Physiol Biochem · 2026 Jul · PMID 42263530 · Publisher ↗
Epicotyl dormancy in recalcitrant seeds limits the propagation and conservation of many woody species, yet the mechanisms by which cold stratification promotes shoot emergence remain unclear. Yunnanopilia longistaminea,...
Epicotyl dormancy in recalcitrant seeds limits the propagation and conservation of many woody species, yet the mechanisms by which cold stratification promotes shoot emergence remain unclear. Yunnanopilia longistaminea, an endangered woody vegetable endemic to China, shows pronounced physiological epicotyl dormancy. Here, we combined controlled cold stratification with tissue-resolved physiological, biochemical, molecular, and chemical-inhibitor assays to investigate how low temperature releases epicotyl dormancy in this species. Stratification at 5 °C for 7 days maximized epicotyl emergence, germination potential, and seedling uniformity, whereas prolonged chilling (28-35 days) markedly reduced emergence, revealing a narrow optimal window. Hormone profiling of embryo/seedling axis, endosperm, and testa showed that cold stratification triggered a transient increase in the embryonic GA3/ABA ratio, accompanied by reduced ABA and increased GA levels, together with coordinated changes in IAA and cytokinins among tissues. Cell-wall analyses further indicated increased hemicellulose accumulation, enhanced pectin methylesterase activity, and optimized cellulose status during the optimal stratification period. Expression of genes involved in ABA catabolism, GA biosynthesis, and wall remodeling changed consistently with these physiological responses. Inhibitor experiments using fluridone and paclobutrazol confirmed that ABA-GA rebalancing is required for dormancy release. These results support a model in which cold stratification unlocks epicotyl dormancy through coordinated hormonal reprogramming and cell-wall remodeling across seed tissues, providing a mechanistic basis for improving propagation and ex situ conservation of Y. longistaminea.
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