It is shown that salicylic acid (SA) signaling plays a critical role in potato NHR against the oomycete pathogen Phytophthora capsici, and new insights are provided into the regulatory framework underlying potato-oomycete interactions.
Abstract
Nonhost resistance (NHR) provides durable and broad-spectrum protection against non-adapted pathogens, yet its regulatory mechanisms in crops remain poorly understood. Here, we show that salicylic acid (SA) signaling plays a critical role in potato NHR against the oomycete pathogen Phytophthora capsici. SA-deficient NahG transgenic plants developed spreading water-soaked lesions following inoculation, whereas wild-type plants exhibited only localized necrosis. Exogenous SA treatment partially restored resistance in NahG lines, supporting an important role for SA in potato NHR. Transcriptome analysis revealed that SA deficiency suppressed defense-associated pathways, including MAPK signaling and pathogenesis-related (PR) gene expression, while inducing photosynthesis- and carbohydrate metabolism-associated genes. In addition, transcriptomic data suggested altered hormone-associated signaling, including induction of ABA-, IAA-, and JA-related pathways, indicating broad transcriptional changes in response to SA deficiency. Functional assays further demonstrated that silencing ERF1B enhanced susceptibility, whereas silencing WRKY53 increased resistance, suggesting distinct transcriptional regulatory roles downstream of SA signaling. Together, these findings support a central role for SA in coordinating immune signaling and metabolic responses during potato nonhost resistance. This study provides new insights into the regulatory framework underlying potato-oomycete interactions.
It is shown that MAX3 deficiency reshapes the Arabidopsis rhizosphere by altering ABA and flavonoid accumulation, which is associated with recruitment of beneficial Pseudomonas and enhanced resistance to bacterial wilt.
Mi-Mi Tian, Yi-Ran Zheng, Wen-Hui Cao et al.· Nature Communications· 0 citations
Phosphate (Pi) starvation is a major constraint on crop productivity, yet its impact on disease resistance is poorly understood. Abscisic acid (ABA) is central to abiotic stress responses, but its interplay with nutritional cues and immunity remains elusive. Here, we reveal how Pi starvation enhances rice blast resistance through a complex ABA-mediated signaling network. We found that Pi-starvation rice exhibits elevated ABA, increased accumulation of the phytoalexin sakuranetin (SAK), and enhanced resistance to Magnaporthe oryzae. Strikingly, ABA exerts a biphasic effect on immunity: brief, high-concentration exposure suppresses resistance, while sustained, low-level treatment promotes it by differentially regulating SAK biosynthesis and endogenous ABA homeostasis. We identified the transcription factor OsbZIP12 as the central integrator of these signals. OsbZIP12 directly activates the SAK biosynthesis gene OsNOMT and is itself regulated by distinct inputs from both Pi starvation (ABA-independent) and ABA signaling. Genetic analyses confirmed that OsbZIP12 is essential for this SAK-dependent resistance. Our findings establish a novel Pi-ABA-immunity network orchestrated by OsbZIP12, providing molecular targets for strategies that leverage nutritional stress to enhance crop resilience.
Yu-Qing He, Jitao Hu, Li Jiang et al.· Plant Communications· 0 citations
Assays demonstrated that SlSN2 overexpression suppressed ToMMV accumulation and infection, likely via enhanced lignin biosynthesis, suggesting a potential role for SlSN2 in contributing to ToMMV resistance, independent of the known Tm‑2² pathway.
Accumulation of silicon (Si) is known to confer resistance in plants against abiotic and biotic stresses; however, questions remain about the underlying mechanisms of Si-mediated resistance against insect herbivores. We investigated the Si-mediated resistance mechanisms in rice against fall armyworm,
Spodoptera frugiperda,
using the
OsLsi1
mutant rice (cv. Nipponbare) lines deficient in Si uptake from the soil.
We investigated these questions using a multidisciplinary approach, combining bioassays of insect and plant growth and biochemical quantification of defense metabolites, phytohormones, and volatiles. Further, we studied constitutive and herbivory-induced gene expression in Os
Lsi1
rice mutants relative to the wild type (WT). Moreover, we detected high-impact SNPs/InDels associated with plant–insect interactions, and integrated these variants with expression signatures across mutants and WT.
Si played a key role in mediating constitutive resistance to FAW, but Si content did not substantially alter induced responses. High Si content promoted compensatory growth post-herbivory and had no effect on constitutive or induced activities of peroxidases, polyphenol oxidases, trypsin inhibitors, and jasmonic acid. Low Si plants constitutively emitted higher levels of certain terpene volatiles. Comparative transcriptomics across mutants and WT showed that Si modulates gene expression under both constitutive and post-herbivory. Plants with high Si levels appear well defended but also capable of allocating resources to re-growth than low Si plants. Genes including
OsbHLH024, OsLsi1, OsMSH3
,
OsARC5, OsCKX2
, and
OsBBX3
are candidates for engineering rice varieties with enhanced herbivory resistance.
These results suggest that Si-deficient rice lines are genetically and transcriptionally less equipped to resistance.
J. Sharma, Chanderkant Chaudhary, Rajat Pruthi et al.· Plant and Soil· 0 citations
Aphids are one of the important agricultural pests causing substantial yield losses in crops grown across the globe. Aphids are known to cause direct feeding damages and indirect losses due to sooty mold development and plant virus transmission. Plants respond to these attacks by mounting a complex defense response at the infested sites and systemic levels. This multilayered defense response involves a highly coordinated network of phytohormones and other signalling components like Ca2+, mitogen activated protein kinases and reactive oxygen species. Key to these complex responses is a well-regulated gene expression involving several transcription factors. A wide range of transcription factors are structurally and functionally characterized across some model plants and in a few agronomically important crops. These transcription factors play diverse roles such as defense gene expression modulation, regulation of hormone signaling, secondary metabolism, oxidative stress response, cell wall modifications, and phloem-based defense. Understanding the integration of signaling pathways, hormone crosstalk, and transcription factor mediated regulation provides a framework for practical applications, including breeding, genome editing, and elicitor-based strategies. This review highlights how plant defense signaling and transcriptional regulation against aphids can be harnessed to develop sustainable and novel pest management solutions.
V. Patil, Rizwana Rehsawla, Apurba K. Barman· Stress Biology· 0 citations
The RNA polymerase II C-terminal domain (CTD) phosphatase CPL1/FRY2 is a multifunctional regulator involved in diverse stress responses, yet its role in orchestrating hormone-mediated immunity remains poorly understood. Here, we demonstrate that CPL1 regulates ABA biosynthesis and modulates SA/JA-associated defence responses in Arabidopsis thaliana. Loss of CPL1 function compromises resistance to the hemibiotrophic bacterial pathogen Pseudomonas syringae pv. tomato DC3000 (Pst DC3000), coinciding with suppressed SA signalling and ectopic activation of JA-, ethylene-, and abscisic acid (ABA)-responsive genes. Hormone profiling revealed that upon Pst DC3000 infection, cpl1 mutants specifically accumulated ABA, but not SA, JA, or ethylene. Epistasis analyses showed that this ABA accumulation stems from the derepression of the seed-specific transcription factor FUSCA3 (FUS3) in vegetative tissues, which in turn drives expression of the ABA biosynthetic gene NCED3. Chromatin immunoprecipitation analyses further revealed that FUS3 silencing in wild-type plants is maintained by repressive epigenetic marks, including low histone acetylation and high H3K9me2/3 levels, modifications that are disrupted in cpl1 mutants. Consequently, CPL1 promotes resistance to biotrophic/hemibiotrophic pathogens by epigenetically silencing FUS3 to prevent pathogen-induced ABA biosynthesis, thereby modulating SA/JA-associated defence responses. Our findings position CPL1 as a key integrator of epigenetic regulation, hormone crosstalk, and pathogen-specific immune tuning.
Lei He, Zhenjiang Wu, Ye Jin et al.· Plant, Cell and Environment· 0 citations
We use cookies to run the site and, with your consent, for analytics and to show ads.
See our Cookie Policy.
