Overexpression of OsPUB41, a Rice E3 ubiquitin ligase induced by cell wall degrading enzymes, enhances immune responses in Rice and Arabidopsis

Abstract Background Cell wall degrading enzymes (CWDEs) induce plant immune responses and E3 ubiquitin ligases are known to play important roles in regulating plant defenses. Expression of the rice E3 ubiquitin ligase, OsPUB41, is enhanced upon treatment of leaves with Xanthomonas oryzae pv. oryzae (Xoo) secreted CWDEs such as Cellulase and Lipase/Esterase. However, it is not reported to have a role in elicitation of immune responses. Results Expression of the rice E3 ubiquitin ligase, OsPUB41, is induced when rice leaves are treated with either CWDEs, pathogen associated molecular patterns (PAMPs), damage associated molecular patterns (DAMPs) or pathogens. Overexpression of OsPUB41 leads to induction of callose deposition, enhanced tolerance to Xoo and Rhizoctonia solani infection in rice and Arabidopsis respectively. In rice, transient overexpression of OsPUB41 leads to enhanced expression of PR genes and SA as well as JA biosynthetic and response genes. However, in Arabidopsis, ectopic expression of OsPUB41 results in upregulation of only JA biosynthetic and response genes. Transient overexpression of either of the two biochemically inactive mutants (OsPUB41C40A and OsPUB41V51R) of OsPUB41 in rice and stable transgenics in Arabidopsis ectopically expressing OsPUB41C40A failed to elicit immune responses. This indicates that the E3 ligase activity of OsPUB41 protein is essential for induction of plant defense responses. Conclusion The results presented here suggest that OsPUB41 is possibly involved in elicitation of CWDE triggered immune responses in rice.

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Action of Multiple Cell Wall–Degrading Enzymes Is Required for Elicitation of Innate Immune Responses During Xanthomonas oryzae pv. oryzae Infection in Rice

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-02-16-0039-r ◽

2016 ◽

Vol 29 (8) ◽

pp. 599-608 ◽

Cited By ~ 9

Author(s):

Lavanya Tayi ◽

Roshan Maku ◽

Hitendra Kumar Patel ◽

Ramesh V. Sonti

Keyword(s):

Cell Wall ◽

Immune Responses ◽

Plant Cell Wall ◽

Defense Responses ◽

Secretion System ◽

Xanthomonas Oryzae ◽

Cell Wall Degrading Enzymes ◽

Degrading Enzymes ◽

Type 3 Secretion System ◽

Type 3

Xanthomonas oryzae pv. oryzae secretes a number of plant cell wall–degrading enzymes (CWDEs) whose purified preparations induce defense responses in rice. These defense responses are suppressed by X. oryzae pv. oryzae using type 3 secretion system (T3SS) effectors and a type 3 secretion system mutant (T3SS−) of X. oryzae pv. oryzae is an inducer of rice defense responses. We assessed the role of individual CWDEs in induction of rice defense responses during infection, by mutating them in the genetic background of a T3SS−. We mutated the genes for five different plant CWDEs secreted by X. oryzae pv. oryzae, including two cellulases (clsA and cbsA), one xylanase (xyn), one pectinase (pglA), and an esterase (lipA), singly in a T3SS− background. We have demonstrated that, as compared with a T3SS− of X. oryzae pv. oryzae, a cbsA−T3SS−, a clsA−T3SS−, and a xyn−T3SS− are deficient in induction of rice immune responses such as callose deposits and programmed cell death. In comparison, a lipA− T3SS− and a pglA−T3SS− is as efficient in induction of host defense responses as a T3SS−. Overall, these results indicate that the collective action of X. oryzae pv. oryzae–secreted ClsA, CbsA, and Xyn proteins is required for induction of rice defense responses during infection.

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The dual function receptor kinase, OsWAKL21.2, is involved in elaboration of lipaseA/esterase induced immune responses in rice

10.1101/754234 ◽

2019 ◽

Author(s):

Kamal Kumar Malukani ◽

Ashish Ranjan ◽

Hota Shiva Jyothi ◽

Hitendra Kumar Patel ◽

Ramesh V. Sonti

Keyword(s):

Cell Wall ◽

Immune Responses ◽

Plant Pathogens ◽

Plant Cell Wall ◽

Ectopic Expression ◽

Dual Function ◽

Receptor Kinase ◽

Cell Wall Degrading Enzymes ◽

Cell Wall Damage

AbstractPlant pathogens secrete cell wall degrading enzymes (CWDEs) to degrade various components of the plant cell wall. Plants sense this cell wall damage as a mark of infection and induce immune responses. Little is known about the plant functions that are involved in the elaboration of cell wall damage-induced immune responses. Transcriptome analysis revealed that a rice receptor kinase, WALL-ASSOCIATED KINASE-LIKE 21 (OsWAKL21.2), is upregulated following treatment with either Xanthomonas oryzae pv. oryzae (Xoo, a bacterial pathogen) or lipaseA/esterase (LipA: a CWDE of Xoo). Downregulation of OsWAKL21.2 attenuates LipA mediated immune responses. Overexpression of OsWAKL21.2 in rice mimics LipA treatment mediated induction of immune responses and enhanced expression of defence related genes, indicating it could be involved in the perception of LipA induced cell wall damage in rice. OsWAKL21.2 is a dual function kinase having in-vitro kinase and guanylate cyclase (GC) activities. Ectopic expression of OsWAKL21.2 in Arabidopsis also activates plant immune responses. Interestingly, OsWAKL21.2 needs kinase activity to activate rice immune responses while in Arabidopsis it needs GC activity. Our study reveals a novel receptor kinase involved in elaboration of cell wall damage induced rice immune responses that can activate similar immune responses in two different species via two different mechanisms.One sentence SummaryA novel rice receptor WAKL21 that sense cell wall damage caused by Xanthomonas secreted cell wall degrading enzyme to induce immune responses.

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Ectopic Expression of a Cell-Wall-Degrading Enzyme-Induced OsAP2/ERF152 Leads to Resistance against Bacterial and Fungal Infection in Arabidopsis

Phytopathology ◽

10.1094/phyto-10-19-0395-r ◽

2020 ◽

Vol 110 (4) ◽

pp. 726-733 ◽

Cited By ~ 1

Author(s):

Shakuntala E. Pillai ◽

Chandan Kumar ◽

Madhumita Dasgupta ◽

Bipin K. Kumar ◽

Sridivya Vungarala ◽

...

Keyword(s):

Cell Wall ◽

Immune Responses ◽

Pseudomonas Syringae ◽

Fungal Pathogens ◽

Ectopic Expression ◽

Ethylene Response Factor ◽

Cell Wall Degrading Enzymes ◽

Callose Deposition ◽

Transient Activation ◽

Mitogen Activated Protein

Pathogen secreted cell-wall-degrading enzymes (CWDEs) induce plant innate immune responses. The expression of rice transcription factor APETALA2/ethylene response factor-152 (OsAP2/ERF152) is enhanced in leaves upon treatment with different CWDEs and upon wounding. Ectopic expression of OsAP2/ERF152 in Arabidopsis leads to induction of immune responses such as callose deposition and upregulation of both salicylic acid- and jasmonic acid/ethylene-responsive defense genes. Arabidopsis transgenics expressing OsAP2/ERF152 exhibited resistance to infections caused by both bacterial and fungal pathogens (Pseudomonas syringae pv. tomato DC3000 and Rhizoctonia solani AG1-IA, respectively). Ectopic expression of OsAP2/ERF152 results in transient activation of mitogen-activated protein kinases 3/6 (MPK3/6), which could be leading to the induction of a broad range immunity in Arabidopsis.

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PUB4, a CERK1-Interacting Ubiquitin Ligase, Positively Regulates MAMP-Triggered Immunity in Arabidopsis

Plant and Cell Physiology ◽

10.1093/pcp/pcz151 ◽

2019 ◽

Vol 60 (11) ◽

pp. 2573-2583 ◽

Cited By ~ 6

Author(s):

Yoshitake Desaki ◽

Shohei Takahashi ◽

Kenta Sato ◽

Kanako Maeda ◽

Saki Matsui ◽

...

Keyword(s):

Immune Responses ◽

Ubiquitin Ligase ◽

Induced Defense ◽

E3 Ubiquitin Ligase ◽

Reactive Oxygen Species Generation ◽

Defense Responses ◽

Knockout Mutant ◽

Double Knockout ◽

Defense Gene Expression ◽

Callose Deposition

Abstract Lysin motif (LysM) receptor-like kinase CERK1 is a co-receptor essential for plant immune responses against carbohydrate microbe-associated molecular patterns (MAMPs). Concerning the immediate downstream signaling components of CERK1, receptor-like cytoplasmic kinases such as PBL27 and other RLCK VII members have been reported to regulate immune responses positively. In this study, we report that a novel CERK1-interacting E3 ubiquitin ligase, PUB4, is also involved in the regulation of MAMP-triggered immune responses. Knockout of PUB4 resulted in the alteration of chitin-induced defense responses, indicating that PUB4 positively regulates reactive oxygen species generation and callose deposition but negatively regulates MAPK activation and defense gene expression. On the other hand, detailed analyses of a double knockout mutant of pub4 and sid2, a mutant of salicylic acid (SA) synthesis pathway, showed that the contradictory phenotype of the pub4 mutant was actually caused by abnormal accumulation of SA in this mutant and that PUB4 is a positive regulator of immune responses. The present and recent findings on the role of PUB4 indicate that PUB4 is a unique E3 ubiquitin ligase involved in the regulation of both plant immunity and growth/development.

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