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.
Bibliographical noteFunding Information:
NRK, acknowledges an INSPIRE fellowship from the Department of Science and Technology (DST)
NRK, acknowledges an INSPIRE fellowship from the Department of Science and Technology (DST), Government of India. VG was supported by a post-doctoral fellowship from the Department of Biotechnology, Government of India. This work was supported by the XIIth five year plan project, Plant-Microbe and Soil Interactions (BSC0117) of the Council of Scientific and Industrial Research. RVS is also supported by a JC Bose Fellowship from the Science and Engineering Research Board, Government of India. Apart from financial support, the funding bodies had no role in the design of the study and no role in the collection, analysis, and interpretation of data or in writing the manuscript.
© 2019 The Author(s).
- Cell wall degrading enzymes
- Damage associated molecular patterns
- E3 ubiquitin ligase
- Plant immunity and Rhizoctonia solani