scholarly journals Ectopic Expression of Grapevine Gene VaRGA1 in Arabidopsis Improves Resistance to Downy Mildew and Pseudomonas syringae pv. tomato DC3000 But Increases Susceptibility to Botrytis cinerea

2019 ◽  
Vol 21 (1) ◽  
pp. 193
Author(s):  
Shanshan Tian ◽  
Xiangjing Yin ◽  
Peining Fu ◽  
Wei Wu ◽  
Jiang Lu

The protein family with nucleotide binding sites and leucine-rich repeat (NBS-LRR) in plants stimulates immune responses caused by effectors and can mediate resistance to hemi-biotrophs and biotrophs. In our previous study, a Toll-interleukin-1(TIR)-NBS-LRR gene cloned from Vitis amurensis “Shuanghong”, VaRGA1, was induced by Plasmopara viticola and could improve the resistance of tobacco to Phytophthora capsici. In this study, VaRGA1 in “Shuanghong” was also induced by salicylic acid (SA), but inhibited by jasmonic acid (JA). To investigate whether VaRGA1 confers broad-spectrum resistance to pathogens, we transferred this gene into Arabidopsis and then treated with Hyaloperonospora arabidopsidis (Hpa), Botrytis cinerea (B. cinerea), and Pseudomonas syringae pv. tomato DC3000 (PstDC3000). Results showed that VaRGA1 improved transgenic Arabidopsis thaliana resistance to the biotrophic Hpa and hemi-biotrophic PstDC3000, but decreased resistance to the necrotrophic B. cinerea. Additionally, qPCR assays showed that VaRGA1 plays an important role in disease resistance by activating SA and inhibiting JA signaling pathways. A 1104 bp promoter fragment of VaRGA1 was cloned and analyzed to further elucidate the mechanism of induction of the gene at the transcriptional level. These results preliminarily confirmed the disease resistance function and signal regulation pathway of VaRGA1, and contributed to the identification of R-genes with broad-spectrum resistance function.

2008 ◽  
Vol 21 (10) ◽  
pp. 1285-1296 ◽  
Author(s):  
Ruth K. Genger ◽  
Grace I. Jurkowski ◽  
John M. McDowell ◽  
Hua Lu ◽  
Ho Won Jung ◽  
...  

Arabidopsis dnd1 and dnd2 mutants lack cyclic nucleotide-gated ion channel proteins and carry out avirulence or resistance gene–mediated defense with a greatly reduced hypersensitive response (HR). They also exhibit elevated broad-spectrum disease resistance and constitutively elevated salicylic acid (SA) levels. We examined the contributions of NPR1, SID2 (EDS16), NDR1, and EIN2 to dnd phenotypes. Mutations that affect SA accumulation or signaling (sid2, npr1, and ndr1) abolished the enhanced resistance of dnd mutants against Pseudomonas syringae pv. tomato and Hyaloperonospora parasitica but not Botrytis cinerea. When SA-associated pathways were disrupted, the constitutive activation of NPR1-dependent and NPR1-independent and SA-dependent pathways was redirected toward PDF1.2-associated pathways. This PDF1.2 overexpression was downregulated after infection by P. syringae. Disruption of ethylene signaling abolished the enhanced resistance to B. cinerea but not P. syringae or H. parasitica. However, loss of NPR1, SID2, NDR1, or EIN2 did not detectably alter the reduced HR in dnd mutants. The susceptibility of dnd ein2 plants to B. cinerea despite their reduced-HR phenotype suggests that cell death repression is not the primary cause of dnd resistance to necrotrophic pathogens. The partial restoration of resistance to B. cinerea in dnd1 npr1 ein2 triple mutants indicated that this resistance is not entirely EIN2 dependent. The above findings indicate that the broad-spectrum resistance of dnd mutants occurs due to activation or sensitization of multiple defense pathways, yet none of the investigated pathways are required for the reduced-HR phenotype.


2020 ◽  
Vol 11 ◽  
Author(s):  
Huijuan Zhang ◽  
Longfei Yin ◽  
Fengming Song ◽  
Ming Jiang

SKIP, a component of the spliceosome, is involved in numerous signaling pathways. However, there is no direct genetic evidence supporting the function of SKIP in defense responses. In this paper, two SKIPs, namely, SlSKIP1a and SlSKIP1b, were analyzed in tomato. qRT-PCR analysis showed that the SlSKIP1b expression was triggered via Pseudomonas syringae pv. tomato (Pst) DC3000 and Botrytis cinerea (B. cinerea), together with the defense-associated signals. In addition, the functions of SlSKIP1a and SlSKIP1b in disease resistance were analyzed in tomato through the virus-induced gene silencing (VIGS) technique. VIGS-mediated SlSKIP1b silencing led to increased accumulation of reactive oxygen species (ROS), along with the decreased expression of defense-related genes (DRGs) after pathogen infection, suggesting that it reduced B. cinerea and Pst DC3000 resistance. There was no significant difference in B. cinerea and Pst DC3000 resistance in TRV-SlSKIP1a-infiltrated plants compared with the TRV-GUS-silencing counterparts. As suggested by the above findings, SlSKIP1b plays a vital role in disease resistance against pathogens possibly by regulating the accumulation of ROS as well as the expression of DRGs.


2021 ◽  
Author(s):  
Xingyu An ◽  
Hui Zhang ◽  
Jinlu Li ◽  
Rui Yang ◽  
Qianchun Zeng ◽  
...  

Abstract Background: The molecular mechanism of durable and broad-spectrum resistance to rice blast disease in japonica rice variety is still very little known. Ziyu44, a local japonica rice variety in Yunnan Province of China, has shown durable broad-spectrum blast resistance for more than 30 years, and provides an opportunity for us to explore the molecular basis of broad-spectrum resistance to rice blast in japonica rice variety.Methods and Results: We conducted a comparative study of mycelium growth, aposporium formation, the accumulation of salicylate(SA), jasmonate(JA) and H2O2, the expression of SA- and JA-associated genes between Ziyu44 and susceptible variety Jiangnanxiangnuo (JNXN) upon M. oryzae infection. We found that appressorium formation and invasive hyphae extention were greatly inhibited in Ziyu 44 leaves compared with that in JNXN leaves. Both Ziyu 44 and JNXN plants maintained high levels of baseline SA and did not show increased accumulation of SA after inoculation with M. oryzae, while the levels of baseline JA in Ziyu 44 and JNXN plants were relatively low, and the accumulation of JA exhibited markedly increased in Ziyu 44 plants upon M. oryzae infection. The expression levels of key genes involving JA and SA signaling pathway OsCOI1b, OsNPR1, OsMPK6 as well as pathogenesis-related (PR) genes OsPR1a, OsPR1b and OsPBZ1, were markedly up-regulated in Ziyu44. Conclusions: The level of endogenous JA is critical for synchronous activation of SA and JA signaling pathway, up-regulating PR gene expression and enhancing disease resistance against rice blast in Ziyu44.


2019 ◽  
Vol 32 (5) ◽  
pp. 566-582 ◽  
Author(s):  
Shixia Liu ◽  
Xi Yuan ◽  
Yuyan Wang ◽  
Hui Wang ◽  
Jiali Wang ◽  
...  

Stress-associated proteins (SAPs) are A20 and AN1 domain–containing proteins, some of which play important roles in plant stress signaling. Here, we report the involvement of tomato SlSAP family in immunity. SlSAPs responded with different expression patterns to Botrytis cinerea and defense signaling hormones. Virus-induced gene silencing of each of the SlSAP genes and disease assays revealed that SlSAP4 and SlSAP10 play roles in immunity against B. cinerea. Silencing of SlSAP4 resulted in attenuated immunity to B. cinerea, accompanying increased accumulation of reactive oxygen species and downregulated expression of jasmonate and ethylene (JA/ET) signaling-responsive defense genes. Transient expression of SlSAP4 in Nicotiana benthamiana led to enhanced resistance to B. cinerea. Exogenous application of methyl jasmonate partially restored the resistance of the SlSAP4-silenced plants against B. cinerea. SlSAP4 interacted with three of four SlRAD23 proteins. The A20 domain in SlSAP4 and the Ub-associated domains in SlRAD23d are critical for SlSAP4-SlRAD23d interaction. Silencing of SlRAD23d led to decreased resistance to B. cinerea, but silencing of each of other SlRAD23s did not affect immunity against B. cinerea. Furthermore, silencing of SlSAP4 and each of the SlRAD23s did not affect immunity to Pseudomonas syringae pv. tomato DC3000. These data suggest that SlSAP4 contributes positively to tomato immunity against B. cinereal through affecting JA/ET signaling and may be involved in the substrate ubiquitination process via interacting with SlRAD23d.


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