The Tian Zhendong team and collaborators at Huazhong Agricultural University revealed the mechanisms by which two E3 ubiquitin-linked enzyme cascades regulate the plant immune response.

Please click "plant reports" above to follow us! The first time to understand the latest progress in plant science! On January 7, 2020, plant Communications published a research paper on the collaboration between Professor Paul birch of Dundee University / James Hutton Institute and Professor Tian Zhendong of Huazhong Agricultural University, revealing the mechanism of E3 ubiquitin ligase cascade regulating plant immune response.ubiquitin modified post transcriptional regulation plays an important role in plant growth and immune regulation.many E3 ubiquitin ligases regulate plant immune response positively or negatively by promoting the degradation of their substrates.stpub17 is a positive regulator of immune response. Overexpression or transient expression of stpub17 in potato can improve late blight resistance. Interference with VIGS in potato or silencing VIGS in Ben's tobacco can reduce late blight resistance. Interference with pub17 can specifically affect CF4 / AVR4 However, it did not affect the anaphylaxis induced by Phytophthora infestans INF1 and potato late blight resistance gene / avirulence gene pairs (R3a / Avr3a, sto / ipio and rvrnt1 / avrvrnt1) induced by Phytophthora infestans INF1 (he et al., 2015).the E3 ubiquitin ligase pob1 containing BTB / back conserved domain is a negative regulator of immune response. Transient expression promotes the spread of Phytophthora infestans, and inhibits INF1, CF4 / AVR4, PTO / AvrPto and R3a / Avr3a And potato antiviral gene and virus coat protein (Rx / PVX CP) mediated cell death.pob1 interacts with pub17 in the nucleus. Pub17 is one of the targets of pob1. Pob1 achieves one negative regulation of E3 ubiquitin protein and another positive regulation of E3 ubiquitin through degradation of pub17 (orosa and he et al., 2017).further studies found that the target of pub17 was stkh17, an RNA binding protein (RBP) protein located in the nucleus containing khomology (KH) domain, which could degrade stkh17.stable expression of kh17 in potato or transient expression in tobacco could reduce late blight resistance and inhibit CF4 / AVR4 immune response, while interference kh17 increased late blight resistance, indicating stkh17 was a negative immune regulator.stkh17 RBP domain mutant stkh17 gddg lost negative immune regulation function, indicating that RNA binding ability is required for stkh17 to perform negative regulation function (McLellan et al., 2020).the above research system reveals how the two E3 ubiquitin ligases can finely regulate plant immune response through cascading degradation of their respective targets.please click "read original" in the lower left corner to view the original paper.long press the QR code below to follow plant reports! Pay attention to the latest research progress of agricultural science and plant science!