Ubiquitination,a critical post-translational modification,plays a pivotal role in fine tuning the immune responses of plants.The tomato(Solanum lycopersicum)suffers significant yield and quality losses caused by the d...Ubiquitination,a critical post-translational modification,plays a pivotal role in fine tuning the immune responses of plants.The tomato(Solanum lycopersicum)suffers significant yield and quality losses caused by the devastating pathogen Botrytis cinerea.We have discovered the role of SlRAE1,a gene encoding an E3 ubiquitin ligase,as a pivotal negative regulator of resistance to B.cinerea.SlRAE1 interacts with SlSKP1,a component of the SKP1–Cullin1–F-box(SCF)complex,to modulate the protein stability of the transcription factor SlWRKY1 through the 26S proteasome pathway.SlWRKY1 targets and inhibits the transcription of SlJAZ7,a suppressor of jasmonic acid(JA)signaling,thereby activating the JA-induced defense system and affecting tomato susceptibility to B.cinerea.The resistance enhancement observed with knock-out SlRAE1 was reduced when SlWRKY1 was also knocked out,highlighting SlWRKY1's role in SlRAE1's regulation of tomato defense against B.cinerea.Our findings elucidate the defense mechanism in tomato and suggest that targeting SlRAE1,by modulating SlWRKY1 stability,could help to develop resistant tomato varieties.These insights have broader implications for using gene-editing technologies to enhance crop defense against fungi.展开更多
Ubiquitin-26S proteasome system （UPS） has been shown to play central roles in light and hormone-regulated plant growth and development. Previously, we have shown that MAX2, an F-box protein, positively regulates fac...Ubiquitin-26S proteasome system （UPS） has been shown to play central roles in light and hormone-regulated plant growth and development. Previously, we have shown that MAX2, an F-box protein, positively regulates facets of photomorphogenic development in response to light. However, how MAX2 controls these responses is still unknown. Here, we show that MAX2 oppositely regulates GA and ABA biosynthesis to optimize seed germination in response to light. Dose-response curves showed that max2 seeds are hyposensitive to GA and hypersensitive to ABA in seed ger- mination responses. RT-PCR assays demonstrated that the expression of GA biosynthetic genes is down-regulated, while the expression of GA catabolic genes is up-regulated in the rnax2 seeds compared to wild-type. Interestingly, expression of both ABA biosynthetic and catabolic genes is up-regulated in the max2 seeds compared to wild-type. Treatment with an auxin transport inhibitor, NPA, showed that increased auxin transport in max2 seedlings contributes to the long hypocotyl phenotype under light. Moreover, light-signaling phenotypes are restricted to max2, as the biosynthetic mutants in the strigolactone pathway, max1, max3, and rnax4, did not display any defects in seed germination and seedling de-etiolation compared to wild-type. Taken together, these data suggest that MAX2 modulates multiple hormone pathways to affect photomorphogenesis.展开更多
The mechanism by which the plant hormone auxin regulates gene expression has been shown to involve regulated degradation, through the ubiquitin-proteasome pathway, of transcriptional repressor proteins. However, the k...The mechanism by which the plant hormone auxin regulates gene expression has been shown to involve regulated degradation, through the ubiquitin-proteasome pathway, of transcriptional repressor proteins. However, the key first component in this pathway, the receptor that binds auxin and initiates auxin signaling, has remained a mystery. Two recent papers identify the F-box protein TIR1, part of the complex that attaches ubiquitin to its targets, as an auxin receptor. This breakthrough reveals a new mode of signal transduction and lays the groundwork for a more complete understanding of auxin physiology.展开更多
基金supported by the National Natural Science Foundation of China (32172599)the Beijing Rural Revitalization Agricultural Science and Technology Project (NY2401080000)+3 种基金the Beijing Agriculture Innovation Consortium (BAIC012025)the support from the Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Cropsthe Engineering Research Center of Breeding and Propagation of Horticultural Cropsthe 2115 Talent Development Program of China Agricultural University
文摘Ubiquitination,a critical post-translational modification,plays a pivotal role in fine tuning the immune responses of plants.The tomato(Solanum lycopersicum)suffers significant yield and quality losses caused by the devastating pathogen Botrytis cinerea.We have discovered the role of SlRAE1,a gene encoding an E3 ubiquitin ligase,as a pivotal negative regulator of resistance to B.cinerea.SlRAE1 interacts with SlSKP1,a component of the SKP1–Cullin1–F-box(SCF)complex,to modulate the protein stability of the transcription factor SlWRKY1 through the 26S proteasome pathway.SlWRKY1 targets and inhibits the transcription of SlJAZ7,a suppressor of jasmonic acid(JA)signaling,thereby activating the JA-induced defense system and affecting tomato susceptibility to B.cinerea.The resistance enhancement observed with knock-out SlRAE1 was reduced when SlWRKY1 was also knocked out,highlighting SlWRKY1's role in SlRAE1's regulation of tomato defense against B.cinerea.Our findings elucidate the defense mechanism in tomato and suggest that targeting SlRAE1,by modulating SlWRKY1 stability,could help to develop resistant tomato varieties.These insights have broader implications for using gene-editing technologies to enhance crop defense against fungi.
文摘Ubiquitin-26S proteasome system （UPS） has been shown to play central roles in light and hormone-regulated plant growth and development. Previously, we have shown that MAX2, an F-box protein, positively regulates facets of photomorphogenic development in response to light. However, how MAX2 controls these responses is still unknown. Here, we show that MAX2 oppositely regulates GA and ABA biosynthesis to optimize seed germination in response to light. Dose-response curves showed that max2 seeds are hyposensitive to GA and hypersensitive to ABA in seed ger- mination responses. RT-PCR assays demonstrated that the expression of GA biosynthetic genes is down-regulated, while the expression of GA catabolic genes is up-regulated in the rnax2 seeds compared to wild-type. Interestingly, expression of both ABA biosynthetic and catabolic genes is up-regulated in the max2 seeds compared to wild-type. Treatment with an auxin transport inhibitor, NPA, showed that increased auxin transport in max2 seedlings contributes to the long hypocotyl phenotype under light. Moreover, light-signaling phenotypes are restricted to max2, as the biosynthetic mutants in the strigolactone pathway, max1, max3, and rnax4, did not display any defects in seed germination and seedling de-etiolation compared to wild-type. Taken together, these data suggest that MAX2 modulates multiple hormone pathways to affect photomorphogenesis.
基金the National Natural Science Foundation of China，Science Publication Foundation of the Chinese Academy of Sciences
文摘The mechanism by which the plant hormone auxin regulates gene expression has been shown to involve regulated degradation, through the ubiquitin-proteasome pathway, of transcriptional repressor proteins. However, the key first component in this pathway, the receptor that binds auxin and initiates auxin signaling, has remained a mystery. Two recent papers identify the F-box protein TIR1, part of the complex that attaches ubiquitin to its targets, as an auxin receptor. This breakthrough reveals a new mode of signal transduction and lays the groundwork for a more complete understanding of auxin physiology.
