J. Plant Physiol. [JOURNAL]
Sun
200 papers
Different types of electrical and calcium signals have different susceptibility to diethyl ether anaesthesia in carnivorous sundew plants.
Pavlovič A, Polášková D, Hřivňacký M
J Plant Physiol · 2026 Jun · PMID 42401073 · Publisher ↗
Plants use electrical and Ca signaling to trigger defence responses. The carnivorous sundew plant (Drosera) co-opted plant defence mechanisms for botanical carnivory and uses electrical and Ca signals to capture prey in...
Plants use electrical and Ca signaling to trigger defence responses. The carnivorous sundew plant (Drosera) co-opted plant defence mechanisms for botanical carnivory and uses electrical and Ca signals to capture prey in sticky tentacles. Here, using a transgenic Drosera rotundifolia transformed with a calcium sensor GCaMP6f, we visualized the propagation of electrical and Ca signals in response to trap wounding and tentacle touch. We also tested the effect of the general volatile anaesthetic diethyl ether to inhibit these reactions. Changes in surface electrical potentials and gene expression were also investigated. Wounding induced systemic electrical and Ca signal propagation from the local wounded to systemic traps. Touching the heads of marginal and central inner tentacles induced fast and slow Ca signals, respectively, and only that from central inner tentacles propagated into the trap blade and entered into the neighbouring untouched tentacles. Diethyl ether completely blocked the fast systemic electrical signal propagation as well as the signal from the touched marginal tentacles, in contrast to the central inner tentacles. The marginal tentacles, however, memorized the touch and responded to it during the recovery period, indicating plant calcium memory. The study revealed at least three types of Ca signals in the sundew plant with different susceptibility to anaesthesia, indicating different ion channel mechanisms responsible for their propagation.
Genetic and environmental factors in determining rice panicle morphogenesis.
Zhong X, Zhang W
J Plant Physiol · 2026 Jun · PMID 42391885 · Publisher ↗
The number of spikelets per panicle is a key determinant of rice yield sink capacity. This trait is governed by the dynamic balance between spikelet differentiation and degeneration which is modulated by intricate geneti...
The number of spikelets per panicle is a key determinant of rice yield sink capacity. This trait is governed by the dynamic balance between spikelet differentiation and degeneration which is modulated by intricate genetic programs, hormonal crosstalk, and fluctuating environmental conditions. This review synthesizes current advances in rice panicle morphogenesis from two complementary perspectives: intrinsic regulation, focusing on rice metabolism and hormonal networks through key rice genes, and extrinsic modulation by environmental factors such as water, nutrients, temperature, and light regimes, and thereby proposes future research priorities are proposed in the biological understanding of rice panicle morphogenesis with a view to laying a theoretical foundation for rice breeding and cultivation strategies for high yield.
NOS-derived NO modulates photosynthetic integrity, carbon metabolism and cellular homeostasis in the cyanobacterium Aphanizomenon flos-aquae under methyl viologen stress.
Gupta N, Mehra T, Srivastava A … +1 more , Mishra AK
J Plant Physiol · 2026 Jun · PMID 42391884 · Publisher ↗
Photosynthetic organisms often face environmental challenges that disrupt cellular homeostasis. Of the various protective mechanisms, nitric oxide (NO) is a crucial signaling molecule with diverse regulatory functions. I...
Photosynthetic organisms often face environmental challenges that disrupt cellular homeostasis. Of the various protective mechanisms, nitric oxide (NO) is a crucial signaling molecule with diverse regulatory functions. In mammalian cells, NO is enzymatically synthesized by nitric oxide synthase (NOS) and regulates several physiological processes such as neuronal differentiation, vascular relaxation, synaptic signaling, and immune regulation. Although recent studies have reported the presence of canonical NOS homologs in photosynthetic microorganisms, their function is yet to be elucidated. Hence, this study investigated the role of NOS-derived NO in mitigating the detrimental effects of the herbicide methyl viologen (MV) in the filamentous cyanobacterium Aphanizomenon flos-aquae 2012/KM1/D3. The findings revealed that NOS-derived NO regulated nonphotochemical quenching and alleviated photoinhibition, supporting photosynthetic efficiency under MV stress. At the cellular level, NOS-derived NO curbed lipid peroxidation and preserved membrane integrity, reinforcing structural defenses. Furthermore, it sustained photosystem gene expression and pigment biosynthesis, ensuring that the light-capture machinery remained intact. These protective effects were absent in L-NG-nitroarginine methyl ester-treated cells, in which the expression of gluconeogenic and pentose phosphate pathway enzymes was increased, likely compensating for the deficit in reducing power. Together, these findings establish the multifaceted role of NOS-derived NO signaling in reinforcing photosynthetic resilience.
Developmental stage-stratified leaf defence: β-1,3-glucanase switching and redox crosstalk drive metal tolerance in soybean.
Mészáros P, Motičáková D, Roszival M … +3 more , Šutáková M, Nemeček P, Matušíková I
J Plant Physiol · 2026 Jun · PMID 42385489 · Publisher ↗
Heavy-metal stress forces plants to balance growth with costly defence. Cadmium (Cd), in particular, perturbs redox homeostasis and cell-wall integrity, yet little is known about how these responses are partitioned among...
Heavy-metal stress forces plants to balance growth with costly defence. Cadmium (Cd), in particular, perturbs redox homeostasis and cell-wall integrity, yet little is known about how these responses are partitioned among organs and developmental stages. Here we combine in-gel activity assays to resolve β-1,3-glucanase (PR-2) and antioxidant superoxide dismutase (SOD) isoforms, gene expression profiling and metabolic markers in roots and leaves of three developmental ages (L1-L3) in soybean (Glycine max) exposed to a 0-300 mg Cd kg gradient. PAGE resolved eight enzymatically active isoform fractions; their activities, together with six SOD isoforms, proline and malondialdehyde (MDA), were quantified after Cd exposure. Multivariate analysis revealed that leaf age explained 52% of total variance, whereas Cd dose contributed 23%. While eldest leaves (L1) mounted an enzyme-plus-antioxidant shield and kept MDA lowest, young leaves (L3) switched to cell-wall remodelling, co-inducing acidic β-1,3-glucanases (AcGLU 1/2), stress-responsive β-1,3-glucanase transcripts and SOD 3. Activity of AcGLU 2 and BasGLU 1 correlated positively with both tissue Cd and SOD 1/5, highlighting a tight glucanase-redox module. Data demonstrate that soybean does not deploy a uniform PR response under Cd stress; instead, it activates distinct β-1,3-glucanase/SOD programmes according to tissue age, optimising defence while preserving growth. This age-stratified, isoform-resolved framework provides new targets for breeding Cd-tolerant cultivars and illustrates the energetic logic underlying growth-defence trade-offs in metal-stressed crops.
Water release regulating JsSWEET17 transcriptional expression to promote the female flower bud differentiation of Juglans sigillata.
Li W, Yuan D, Chen J … +4 more , Li C, Huang Y, Zhang W, Pan X
J Plant Physiol · 2026 Jun · PMID 42361429 · Publisher ↗
The accumulation and transport of carbohydrates are among the key factors determining flower bud induction. In this study, water release treatment of J. sigillata at the pre-differentiated stage of female flower buds inc...
The accumulation and transport of carbohydrates are among the key factors determining flower bud induction. In this study, water release treatment of J. sigillata at the pre-differentiated stage of female flower buds increased the proportion of female flower buds in the following year. Additionally, the ratio of carbon and nitrogen (C/N) in leaves, together with the sucrose and fructose contents in female flower buds, also increased. Water release increased the expression of the fructose transporter gene JsSWEET17 and reduced the expression of the sucrose transporter gene JsSWEET1 and the fructose transporter gene JsSWEET9 in female flower buds. JsSWEET1 was highly expressed at the leaf-bud growth point, JsSWEET9 was highly expressed during the morphological differentiation stage of the male flower bud, and JsSWEET17 was highly expressed in the pre-differentiated stage and the morphological differentiation stage of the female flower bud. The fructose content increased significantly in JsSWEET17 transgenic Arabidopsis thaliana, and the expression of flower induction genes AtFT (FLOWERING LOCUS T) and AtSOC1 (SUPPRESSOR OF OVEREXPRESSION OF CO1) was significantly upregulated. The flowering time of the transformed plants was 2-3 days earlier than that of the wild type (WT). The increase in fructose content induced by in vitro feeding resulted in high expression of JsSWEET17 and flowering-induction genes (JsFT, JsSOC1, JsAG (AGAMOUS), JsCO (CONSTANS)) in female flower buds. These results indicate that water release treatment may increase the proportion of female flowers by enhancing the expression of JsSWEET17, increasing fructose content and inducing responses in flowering genes, providing new insights into the molecular mechanism by which sugar transport regulates flower differentiation.
Horse chestnut (Aesculus hippocastanum L.) bud scales harbor photosynthetically active chloroplasts during their entire lifespan.
Enkhbileg E, Skribanek A, Boldizsár I … +1 more , Solymosi K
J Plant Physiol · 2026 Jun · PMID 42349258 · Publisher ↗
Bud scales (cataphylls) protect latent shoot apices and preformed organs in the majority of deciduous trees, yet these modified structures of leaf origin and their potential other functions are rarely studied in detail....
Bud scales (cataphylls) protect latent shoot apices and preformed organs in the majority of deciduous trees, yet these modified structures of leaf origin and their potential other functions are rarely studied in detail. Here, we investigated seasonal and developmental variations in anatomy by bright-field microscopy; plastid ultrastructure by transmission electron microscopy; optical properties, photosynthetic pigment contents and organization by various spectroscopic methods; photosystem II (PSII) activity by Imaging PAM; and gross photosynthesis by infrared gas exchange analysis in outer brownish and inner greenish bud scales of horse chestnut (Aesculus hippocastanum L.) throughout their lifespan, i.e. from their initiation end of spring until their senescence after the bud break next year. The composition of the resin secreted on the outer bud scales was characterized by HPLC-UV-HRMS following acetonic extraction, revealing methoxylated flavonols as the dominant constituents and suggesting additional roles in photoprotection and chemical defense. Both outer and inner bud scales retained structurally intact, photosynthetically competent chloroplasts throughout all seasons, despite low chlorophyll content and limited photosynthetic capacity. Outer scales exhibited strong light-filtering, photoprotective properties, and pronounced seasonal downregulation of photosynthetic performance, besides their known roles in thermal insulation, and environmental shielding. In contrast, inner scales maintained higher chlorophyll content, more stable PSII efficiency during dormancy, and rapidly recovered photosynthetic activity during bud break, indicating a metabolically poised state supporting early spring development. Our findings underscore bud scales' multifunctional roles as protective barriers and active contributors to plant physiology by photosynthesis and the maintenance of chloroplast ultrastructure throughout their lifespan.
Effects of salt stress on seedling growth and anthocyanin synthesis in black goji (Lycium ruthenicum Murray).
Qi Y, Lu Y, Zhang X … +2 more , Qiao F, Qiu QS
J Plant Physiol · 2026 Jun · PMID 42335475 · Publisher ↗
Black goji (Lycium ruthenicum Murray) is a distinctive desert medicinal plant indigenous to western China. It is characterized by its high concentration of anthocyanins, which have antioxidant properties, and is recogniz...
Black goji (Lycium ruthenicum Murray) is a distinctive desert medicinal plant indigenous to western China. It is characterized by its high concentration of anthocyanins, which have antioxidant properties, and is recognized for its significant medicinal and health benefits. However, the mechanism by which salt stress promotes the formation of high-quality black goji is still unclear. This study investigated the effects of salt stress on growth and anthocyanin synthesis in black goji. Our results showed that salt stress inhibited the growth of black goji seedlings and promoted the synthesis and accumulation of anthocyanins. Moreover, salt stress enhanced the regulatory effect of the MBW complex on the promoters of anthocyanin synthesis genes. Interestingly, salt stress promoted the synthesis and accumulation of anthocyanins in the LrAN2 transgenic callus of black goji. Transcriptome and metabolome analyses indicated that LrAN2 promoted the expression of anthocyanin synthesis-related genes and the accumulation of metabolites, and this effect was further enhanced under salt stress. This study provides a basis for understanding the molecular mechanism of anthocyanin synthesis in black goji.
Exogenous calcium modulates oxalic acid metabolism via repression of LcAAE3 and mediates calcium accumulation in litchi pericarp and fruit pedicel.
Li DC, Zhong ZQ, Chen TK … +5 more , Liu YT, Sun YH, Wang HC, Zeng RF, Huang XM
J Plant Physiol · 2026 Aug · PMID 42309000 · Publisher ↗
Calcium plays a crucial role in fruit development and quality formation, yet the regulatory mechanisms underlying calcium distribution and oxalic acid metabolism in litchi remain poorly understood. In this study, the eff...
Calcium plays a crucial role in fruit development and quality formation, yet the regulatory mechanisms underlying calcium distribution and oxalic acid metabolism in litchi remain poorly understood. In this study, the effects of exogenous calcium on calcium accumulation, fruit quality, and oxalic acid metabolism in litchi were investigated through stem infusion experiments using calcium chloride (CaCl) and ethylene glycol-bis(2-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA) treatments. The results demonstrated that exogenous CaCl application significantly enhanced calcium accumulation in pedicel tissues, particularly in the pith, phloem, and xylem, whereas EGTA treatment chelated endogenous calcium ions (Ca) and inhibited this accumulation. Notably, despite increased calcium levels in the pericarp, exogenous CaCl and EGTA applications did not affect fruit quality parameters, including appearance, weight, seed weight, pericarp weight, color, or total soluble solids content. Furthermore, CaCl treatment promoted the formation of insoluble calcium oxalate crystals in both fruit pedicels and pericarp without significantly altering soluble oxalic acid content, suggesting a homeostatic maintenance of oxalic acid levels. Through bioinformatic analysis and enzymatic assays, acyl-activating enzyme 3 (LcAAE3), an oxalyl-CoA synthetase that catalyzes the initial step of oxalic acid degradation, was identified and characterized. LcAAE3 exhibited specific catalytic activity toward oxalic acid and LcAAE3 gene showed markedly higher expression levels than its paralog LcAAE3-1 across litchi tissues. Exogenous CaCl suppressed LcAAE3 expression, while EGTA treatment induced its expression. Virus-induced gene silencing of LcAAE3 in fruit pedicels resulted in significant accumulation of both oxalic acid and calcium oxalate in pedicels and pericarp. In contrast, overexpression of LcAAE3 in tobacco significantly inhibited the accumulation of calcium oxalate and oxalic acid, confirming its role in promoting oxalic acid degradation. These findings reveal that exogenous calcium enhances tissue-specific calcium accumulation and calcium oxalate formation without compromising fruit quality, and establish LcAAE3 as a key regulator of oxalate homeostasis in litchi. This study provides insights into calcium-mediated oxalic acid metabolism and offers a theoretical basis for improving litchi fruit quality through calcium management.
SlCOMT1-dependent melatonin biosynthesis is required for auxin-mediated alleviation of cadmium toxicity in tomato.
Pei ZQ, Ma C, Xing P … +7 more , Li LH, Mou XX, Guo T, Wang L, Wang J, Zheng S, Zhang TG
J Plant Physiol · 2026 Aug · PMID 42275843 · Publisher ↗
Cadmium (Cd) severely inhibits plant growth by disrupting ion homeostasis, impairing redox balance, and inhibiting photosynthesis. Although auxin has been demonstrated to alleviate Cd damage in plants, the downstream sig...
Cadmium (Cd) severely inhibits plant growth by disrupting ion homeostasis, impairing redox balance, and inhibiting photosynthesis. Although auxin has been demonstrated to alleviate Cd damage in plants, the downstream signaling mechanisms remain unclear. In this study, tomato (Solanum lycopersicum L.) seedlings were used to investigate the role of melatonin (MT) in IAA-induced alleviation of Cd damage. exogenous IAA mitigated Cd-induced growth inhibition and decreased its accumulation. The alleviating effects of IAA were associated with increased contents of cell wall components and detoxification-related metabolites, including lignin, cellulose, hemicellulose, pectin, glutathione, and phytochelatins. In addition, IAA alleviated oxidative damage and photosynthetic impairment caused by Cd. Further analysis showed that IAA enhanced the Cd-induced expression of SlCOMT1 (caffeic acid O-methyltransferase 1), a key gene involved in MT biosynthesis, and promoted endogenous MT accumulation. Notably, pharmacological inhibition of MT biosynthesis by p-CPA (CPA) weakened the protective effect of IAA. Genetic evidence showed that SlCOMT1 overexpression enhanced the alleviating effect of IAA, whereas the slcomt1 mutant compromised this effect. Exogenous MT restored the responsiveness of slcomt1 plants to IAA. Together, these findings indicate that SlCOMT1-mediated MT biosynthesis is required for IAA to alleviate Cd toxicity, revealing a new mechanism of IAA-mediated Cd detoxification through MT signaling and providing a theoretical basis for reducing Cd accumulation in crops via genetic improvement or exogenous regulation of the MT pathway.
Phytohormonal orchestration of plant phosphate starvation responses.
Lu KK, Song RF, Fan YP … +10 more , Xu LY, Chen BH, Li SX, Sun MT, Liu GM, Huang XL, Li L, Guo XR, Ren F, Liu WC
J Plant Physiol · 2026 Aug · PMID 42269483 · Publisher ↗
Phosphorus (P) is an essential macronutrient for plant growth and development, yet its availability in soils is frequently limited due to fixation and slow diffusion. To cope with phosphate (Pi) starvation, plants have e...
Phosphorus (P) is an essential macronutrient for plant growth and development, yet its availability in soils is frequently limited due to fixation and slow diffusion. To cope with phosphate (Pi) starvation, plants have evolved sophisticated signaling networks involving multiple phytohormones that coordinate morphological, physiological, and molecular responses. This review provides a comprehensive overview of the roles and mechanisms of major phytohormones, including auxin, cytokinin, ethylene, strigolactones, abscisic acid, jasmonic acid, gibberellins, and brassinosteroids, in regulating plant responses to Pi deficiency. We also highlight recent advances in understanding how phytohormone signaling is coordinated with PHR1, the key transcription factor governing plant Pi starvation responses, including mechanisms of translational regulation, post-translational modifications, and protein-protein interactions. Finally, we propose future research directions for developing crops with improved phosphorus use efficiency through hormonal manipulation.
GSTF10 acts downstream of FERONIA to inhibit pollen germination and tube elongation.
Duan M, Du L, Yan H … +1 more , He Y
J Plant Physiol · 2026 Aug · PMID 42263619 · Publisher ↗
Pollen-stigma interactions constitute the initial step of male-female communication during flowering plant reproduction, ensuring compatible pollen germination and fertilization. In Arabidopsis, the receptor kinase FERON...
Pollen-stigma interactions constitute the initial step of male-female communication during flowering plant reproduction, ensuring compatible pollen germination and fertilization. In Arabidopsis, the receptor kinase FERONIA (FER) regulates this process, but its downstream signaling mechanisms remain incompletely understood. Here, we identify Glutathione S-Transferase Phi 10 (GSTF10) as a FER-interacting protein. Physical interaction between FER and GSTF10 was confirmed by yeast two-hybrid, luciferase complementation, and co-immunoprecipitation assays. In vitro phosphorylation assays showed that FER directly phosphorylates GSTF10. Loss of GSTF10 function led to accelerated pollen hydration on the stigma and reduced reactive oxygen species (ROS) levels in stigma papillae, accompanied by enhanced pollen tube elongation. Genetic epistasis analysis revealed that the fer-4 gstf10-1 double mutant phenocopied the gstf10-1 single mutant in terms of pollen tube length, placing GSTF10 downstream of FER in regulating pollen tube growth. In addition, gstf10 mutants produce more seeds per silique. Collectively, these findings suggest that FER-mediated phosphorylation of GSTF10 contributes to restraining pollen hydration and tube elongation, likely through modulating ROS homeostasis in the stigma. This study uncovers a previously unrecognized signaling module that governs early events of compatible pollination.
Functional characterization of type I chalcone isomerase AmCHI from Astragalus mongholicus and its response mechanism to exogenous hormones.
Wang P, Wang X, Li Z … +6 more , Zhang X, Pan M, Yang K, Wang Z, Ma W, Liu X
J Plant Physiol · 2026 Aug · PMID 42263618 · Publisher ↗
Flavonoids, as the principal bioactive constituents of Astragalus mongholicus, play key roles in multiple physiological processes including plant development and stress adaptation. Chalcone isomerase (CHI) is a key rate-...
Flavonoids, as the principal bioactive constituents of Astragalus mongholicus, play key roles in multiple physiological processes including plant development and stress adaptation. Chalcone isomerase (CHI) is a key rate-limiting enzyme in the flavonoid biosynthetic pathway and directly determines the production efficiency of flavonoids. However, its catalytic mechanism and in vivo functions in A. mongholicus remain to be elucidated. Exogenous hormone treatments revealed that methyl jasmonate, auxin, and ethephon significantly promoted AmCHI expression and flavonoid accumulation, whereas salicylic acid exhibited an inhibitory effect. Subcellular localization analysis showed that AmCHI is predominantly localized to the plasma membrane and the nucleus. Yeast heterologous expression confirmed its specific catalytic activity in converting naringenin chalcone to naringenin. In vivo functional validation in A. mongholicus demonstrated that overexpression of this gene in transgenic hairy roots significantly increased its transcript level by 2.9-3.5 fold compared with the control, and enhanced flavonoid accumulation by 1.3 fold, whereas gene silencing significantly reduced AmCHI expression by 30-50% and decreased total flavonoid content to 30-55% of the control level. In conclusion, this study systematically elucidates the core regulatory role of AmCHI in flavonoid biosynthesis in A. mongholicus, providing an important theoretical foundation for improving the quality of medicinal plants and for future metabolic engineering efforts.
Genome-wide identification of StMAPKKKs and functional characterization of StMAPKKK44 in regulating salt and drought tolerance in potato (Solanum tuberosum L.).
Zhu X, Wang K, Duan X … +9 more , Pang X, Du X, Han Z, Li W, Chen S, Jin H, Chen Z, Zhang Y, Majeed Y
J Plant Physiol · 2026 Aug · PMID 42259055 · Publisher ↗
Mitogen-activated protein kinase kinase kinases (MAPKKKs) play crucial roles in plant signal transduction pathways, particularly in regulating responses to abiotic stresses such as drought, salinity, and temperature extr...
Mitogen-activated protein kinase kinase kinases (MAPKKKs) play crucial roles in plant signal transduction pathways, particularly in regulating responses to abiotic stresses such as drought, salinity, and temperature extremes. StMAPKKK44 was prioritized due to its predicted involvement in upregulation and its potential regulatory role in enhancing abiotic stress tolerance in potato. Here, we conducted a comprehensive bioinformatics analysis and identified 85 StMAPKKK genes in potato. Expression profiling under salt and drought stress revealed that 16 StMAPKKK genes were differentially expressed, with StMAPKKK44 showing significant and sustained upregulation. Subcellular localization assays demonstrated that StMAPKKK44 is localized to the plasma membrane, nucleus, and cytoplasm. Furthermore, the specific interactions of StMAPKKK44 with StMAPKK1/5 were verified using complementary protein-protein interaction approaches, namely yeast two-hybrid (Y2H), bimolecular fluorescence complementation (BiFC), and split-luciferase complementation (SLC). Functional characterization in potato cultivar 'Atlantic' via overexpression (OE) and RNA interference (RNAi) demonstrated that StMAPKKK44-OE lines exhibited improved salt and drought tolerance with enhanced plant height and biomass, whereas StMAPKKK44-RNAi lines showed increased stress sensitivity relative to non-transgenic (NT) controls. The improved stress tolerance in OE plants was associated with a potentiated antioxidant system, evidenced by significantly elevated activities of key enzymes, including ascorbate peroxidase (APX), superoxide dismutase (SOD), catalase (CAT), as well as peroxidase (POD), and the transcript levels of their encoding genes. Furthermore, OE lines accumulated higher levels of osmoprotectants (proline, soluble sugars) and chlorophyll, thereby enhancing osmotic adjustment and photosynthetic capacity. Consequently, oxidative damage indicators, such as malondialdehyde (MDA), hydrogen peroxide (HO), and electrolyte leakage, were markedly reduced in OE plants but increased in RNAi lines. In summary, this study provides the first systematic analysis of the StMAPKKK gene family in potato and clearly demonstrates that StMAPKKK44 enhances tolerance to drought and salt stress by coordinately regulating the antioxidant defense system and osmotic balance. These findings indicate that StMAPKKK44 represents a promising molecular target for developing stress-resilient potato cultivars.
A regulatory network linking NnTPS1, NnTRX and NnSnRK1 modulates energy allocation and flower bud abortion in lotus.
Kuang J, Liang K, Li Y … +3 more , Wang Y, Xu Y, Jin Q
J Plant Physiol · 2026 Aug · PMID 42208411 · Publisher ↗
Lotus (Nelumbo nucifera) is highly sensitive to energy status, and low light frequently triggers flower bud abortion, reducing its ornamental and economic value. In this study, we identified thioredoxin (NnTRX) as a prev...
Lotus (Nelumbo nucifera) is highly sensitive to energy status, and low light frequently triggers flower bud abortion, reducing its ornamental and economic value. In this study, we identified thioredoxin (NnTRX) as a previously unrecognized regulatory component functionally associated with the NnTPS1-NnSnRK1 module involved in energy allocation and reproductive fate in lotus. Energy stress simulated by controlled shading led to a pronounced decrease in NnTPS1 expression and a concomitant increase in NnSnRK1 transcription and kinase activity; these molecular alterations were closely associated with bud abortion. Functional analyses showed that NnTPS1 overexpression significantly mitigated low-light-induced flower bud abortion and suppressed NnSnRK1 activity. Yeast one-hybrid and transient expression assays demonstrated that NnTRX directly binds to and activates the NnSnRK1 promoter, functioning as a previously unrecognized positive regulator. Silencing NnTRX reduced NnSnRK1 levels and markedly alleviated bud abortion. Moreover, both exogenous trehalose application and NnTRX silencing promoted preferential allocation of energy reserves to reproductive organs, thereby enhancing flowering success, as confirmed by Periodic Acid-Schiff (PAS) staining. Collectively, our findings support a regulatory network linking NnTPS1, NnTRX and NnSnRK1 in the control of energy allocation and reproductive development under shade stress, offering theoretical insights and candidate molecular targets for breeding stress-resistant lotus cultivars.
The STE20/Hippo kinase SIK1 interacts with COI1 and negatively regulates the response to jasmonic acid.
Wang Q, Zhang P, Yang Y … +5 more , Wang G, Xin P, Chu J, Wu S, Gong Q
J Plant Physiol · 2026 Aug · PMID 42208410 · Publisher ↗
The Hippo signaling pathway is a highly conserved pathway in metazoans that limits organ size by restricting tissue overgrowth. This pathway is named after one of its key components, the Ste20 family protein kinase Hippo...
The Hippo signaling pathway is a highly conserved pathway in metazoans that limits organ size by restricting tissue overgrowth. This pathway is named after one of its key components, the Ste20 family protein kinase Hippo (Hpo). We previously identified SIK1 in Arabidopsis as a functional orthologue of Hpo and Ste20 and found that the sik1 mutant has smaller lateral organs due to cell cycle exit failure and delayed onset of cell expansion. The plant hormone jasmonic acid (JA) can limit cell proliferation and organ growth, and studies including our own have shown a potential association between SIK1 and JA. In this study, we investigated whether SIK1 is involved in JA biosynthesis, signaling, or response. We found that under normal growth conditions, JA levels and responses were elevated in sik1. However, the JA biosynthetic mutants aos and opr3, as well as the JA receptor mutant coi1, could not suppress the dwarf phenotype of sik1, indicating that the elevated JA response was not the cause of the reduced organ size in sik1. On the other hand, sik1, aos sik1, and opr3 sik1 mutants were all hypersensitive to exogenous JA in primary root elongation, whereas coi1 sik1, like coi1, was insensitive to JA. Furthermore, we found that SIK1 interacts with COI1 both in vitro and in vivo, and negatively regulates the JA response. RNA sequencing analyses further validated that the dwarf phenotype of sik1 was not a result of elevated JA response, but rather, may be due to a failure in cell cycle exit as we had previously reported. Our findings revealed two separate roles of SIK1; it plays a direct positive role in organ size control and a negative role in JA response which is achieved at least partially through its interaction with COI1.
CsMYB6 promotes crocins biosynthesis in response to JA signaling in Crocus sativus L.
Wang S, Lin C, Shi X … +7 more , Zhou A, Chen T, Zheng Y, Shao Q, Zhang L, Ding L, Xing B
J Plant Physiol · 2026 Aug · PMID 42202640 · Publisher ↗
Crocins has been identified as the key bioactive compound in saffron. The plant hormone jasmonate promotes the accumulation of crocins in saffron, but its regulatory mechanism remains unclear. MYB transcription factors a...
Crocins has been identified as the key bioactive compound in saffron. The plant hormone jasmonate promotes the accumulation of crocins in saffron, but its regulatory mechanism remains unclear. MYB transcription factors are essential for regulating plant development and metabolic processes. In this study, a MeJA-responsive R2R3-MYB transcription factor, CsMYB6, was identified. The expression of CsMYB6 showed a strong correlation with the expression of key genes involved in crocins biosynthesis. Overexpression of CsMYB6 in Crocus sativus stigmas enhanced crocin content and upregulated the expression levels of key enzyme genes involved in crocins biosynthesis. Yeast one-hybrid assays confirmed the interaction between CsMYB6 and CsZ-ISO3/CsCCD2 promoters. Dual-LUC assays demonstrated that CsMYB6 binds to and activates the promoter of CsZ-ISO3/CsCCD2. These findings reveal a novel regulatory role of CsMYB6 in MeJA-mediated crocins biosynthesis and propose a "MeJA-CsMYB6-CsZ-ISO3/CsCCD2-crocins" regulatory model, enriching the regulatory network of crocins biosynthesis and laying a foundation for further exploration of the molecular mechanisms underlying saffron secondary metabolism.
Microbial-derived metabolites coordinate growth regulation and stress tolerance in Phalaenopsis orchids.
Maulidah NI, Lin IH, Yen YT … +2 more , Liou TY, Chuang HW
J Plant Physiol · 2026 Jul · PMID 42156212 · Publisher ↗
Microbial metabolites regulate plant growth and stress responses, yet their roles in crassulacean acid metabolism (CAM) plants remain insufficiently characterized. Here, we investigated the effects of metabolites from Ba...
Microbial metabolites regulate plant growth and stress responses, yet their roles in crassulacean acid metabolism (CAM) plants remain insufficiently characterized. Here, we investigated the effects of metabolites from Bacillus licheniformis strain BlCP6, identified by 16S rDNA sequencing and whole-genome analysis, on growth and stress responses in Phalaenopsis orchids. Genome sequencing and metabolite profiling revealed that siderophores represent major bioactive compounds with direct plant growth-promoting potential, whereas osmoprotectants and extracellular lytic enzymes may contribute indirectly by enhancing stress tolerance. Application of BlCP6-derived metabolites significantly promoted leaf growth within three weeks and increased plant fresh weight after twelve weeks. Treated plants exhibited elevated phenylalanine ammonia-lyase activity, increased lignin deposition, enhanced accumulation of total phenolic compounds, and strengthened antioxidant capacity, as reflected by higher activities of ascorbate peroxidase, guaiacol peroxidase, and catalase. These biochemical changes were accompanied by improved tolerance to drought and chilling stress, as evidenced by higher relative water content and reduced membrane lipid peroxidation and electrolyte leakage. Metabolite pretreatment also moderately improved resistance to Fusarium yellow-leaf disease. Immunoblot analyses showed higher apparent accumulation of proteins associated with growth regulation, including zeaxanthin epoxidase, sedoheptulose-1,7-bisphosphatase, plasma membrane H-ATPase, and nitrate reductase. BlCP6 treatment was also associated with increased accumulation of stress-related proteins, including superoxide dismutase, dehydrin, aquaporin, and autophagy-related proteins. Notably, increased accumulation of chloroplastic lipoxygenase is consistent with activation of oxylipin- and jasmonate-related signaling, while enhanced levels of cellulose synthase and pathogenesis-related protein 2 suggest cell wall reinforcement and defense responses. Collectively, BlCP6-derived metabolites appear to induce coordinated plant-wide responses that enhance growth performance and stress tolerance in Phalaenopsis orchids.
Genetic dissection of seed quality traits in mungbean through QTL-seq of recombinant inbred line populations.
Ren C, Qiao J, Qiao L … +5 more , Li B, Hao X, Guo X, Yang F, Huo D
J Plant Physiol · 2026 Jul · PMID 42150373 · Publisher ↗
Mungbean [Vigna radiata (L.) R. Wilczek] has gained increasing popularity in the food industry owing to its unique functional properties and high nutritional value. Improving the protein, starch, and water content of mun...
Mungbean [Vigna radiata (L.) R. Wilczek] has gained increasing popularity in the food industry owing to its unique functional properties and high nutritional value. Improving the protein, starch, and water content of mungbean seeds is a fundamental breeding objective, as these traits are critical determinants of seed quality. However, there have been no systematic reports of identified quantitative trait loci (QTLs) associated with these traits in mungbean. In this study, we generated a recombinant inbred line (RIL) population from a cross between B031 and B2939 and conducted phenotypic evaluation across three distinct environments. Using three QTL mapping methods, we identified 19 QTLs associated with protein content, 16 QTLs for starch content, and 12 QTLs for water content. Among these, qPRO10-1, qSTA8-1, and qWAT7-2 were consistently detected across different environments and mapping methods. Our further investigation identified two candidate genes potentially regulating protein content, one for starch content, and one for water content. These findings provide a solid theoretical foundation for future functional studies on the genetic regulators of these key traits and support the breeding of high-quality mungbean germplasm.
Opinion piece: Moonlighting enzymes as hidden transcriptional regulators of metabolism.
von Steimker J, Fernie AR
J Plant Physiol · 2026 Jul · PMID 42143946 · Publisher ↗
We propose that moonlighting enzymes with dual roles in plant secondary metabolism, as both catalytic components and regulators of biosynthetic gene expression, are likely far more prevalent than currently recognized. He...
We propose that moonlighting enzymes with dual roles in plant secondary metabolism, as both catalytic components and regulators of biosynthetic gene expression, are likely far more prevalent than currently recognized. Here, we focus on the recent discovery of phenylalanine ammonia-lyase (PAL), which catalyzes the first step of the flavonoid pathway and, when sufficient flavonoids are produced, enters the nucleus via post-translational modification to negatively feedback on phenylpropanoid biosynthesis by interacting with the transcription factor TRANSPARENT TESTA 8 (TT8), a component of the MBW transcriptional complex, composed of MYB, basic helix-loop-helix (bHLH), and WD40 proteins. Greater awareness of such multifunctionality will be essential for identifying key regulatory nodes, for instance, through environmental genome-wide association studies. This observation is particularly relevant in secondary metabolism, where rapid and dynamic responses to environmental cues are vital. Recognizing enzymes as potential regulators, rather than merely catalysts, may therefore transform strategies to identify, manipulate and fine-tune control points in plant metabolic pathways.
The regulation of stomatal closure as a key factor to benefit from rising atmospheric [CO] in rice (Oryza sativa L.).
Ancín M, Irigoyen JJ, Aranjuelo I
J Plant Physiol · 2026 Jul · PMID 42127508 · Publisher ↗
Stomata, specialized pores on leaf epidermis, regulate CO uptake and water evaporation in terrestrial plants. Since environmental and biochemical stimuli affect stomatal aperture, its regulation is strongly correlated wi...
Stomata, specialized pores on leaf epidermis, regulate CO uptake and water evaporation in terrestrial plants. Since environmental and biochemical stimuli affect stomatal aperture, its regulation is strongly correlated with photosynthesis. Particularly in rice (Oryza sativa L.), it was demonstrated that stomatal conductance (g) is a major determinant of photosynthetic rate under well-watered conditions. However, little is known about the impact of altered stomatal regulation under CO enrichment on rice leaf physiology and metabolism. In this study, we analyse the physiological and proteomic response of SLAC1-deficient rice plants (slac1) with a constitutive open-stomata phenotype, grown under ambient or elevated CO concentration (a[CO]: 400 vs e[CO]: 700 μmol mol). According to gas-exchange measurements, g and intracellular [CO] were higher in slac1 than in the Wt genotype, while the photosynthetic rate was lower at both [CO]. Although Wt plants were capable to double their biomass under e[CO], any change was observed in the slac1 genotype. This behaviour linked to a higher transpiration rate under e[CO], and a down-regulation of different aquaporins and photosynthetic light reaction proteins, together with the overexpression of proteins related to stress and redox homeostasis, revealed that their inability to close stomata subjected slac1 plants to stressful growing conditions that avoid the CO fertilization effect. In summary, the current study showed that, regulation of stomatal opening is a target process with potential double effect (positive or negative) that has an important impact on leaf metabolism and responsiveness to changing environmental conditions.
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