Deep sowing is a traditional method for drought resistance in maize production,and mesocotyl elongation is strongly associated with the ability of maize to germinate from deep soil.However,little is known about the fu...Deep sowing is a traditional method for drought resistance in maize production,and mesocotyl elongation is strongly associated with the ability of maize to germinate from deep soil.However,little is known about the functional genes and mechanisms regulating maize mesocotyl elongation.In the present study,we identified a plant-specific SIMILAR TO RCD-ONE(SRO) protein family member,ZmSRO1e,involved in maize mesocotyl elongation.The expression of ZmSRO1e is strongly inhibited upon transfer from dark to white light.The loss-of-function zmsro1e mutant exhibited a dramatically shorter mesocotyl than the wild-type in both constant light and darkness,while overexpression of ZmSRO1e significantly promoted mesocotyl elongation,indicating that ZmSRO1e positively regulates mesocotyl elongation.We showed that ZmSRO1e physically interacted with Zmb ZIP61,an ortholog of Arabidopsis ELONGATED HYPOCOTYL 5(HY5) and showed a function similar to that of HY5 in regulating photomorphogenesis.We found that ZmSRO1e repressed the transcriptional activity of Zmb ZIP61 toward target genes involved in the regulation of cell expansion,such as ZmEXPB4 and ZmEXPB6,by interfering with the binding of ZmbZIP61 to the promoters of target genes.Our results provide a new understanding of the mechanism by which SRO regulates photomorphogenesis and highlight its potential application in deep sowing-resistant breeding.展开更多
基金supported by grants from the Natural Science Foundation of Shandong Province (ZR2019ZD16 and ZR2022QC007)the National Natural Science Foundation of China (32171935 and 32372039)+2 种基金Agricultural Variety Improvement Project of Shandong Province (2022LZGC002)the National Key Research and Development Program of China (2022YFD1201700)the Project for Scientific Research Innovation Team of Young Scholars in Colleges and Universities of Shandong Province (2020KJE002)。
文摘Deep sowing is a traditional method for drought resistance in maize production,and mesocotyl elongation is strongly associated with the ability of maize to germinate from deep soil.However,little is known about the functional genes and mechanisms regulating maize mesocotyl elongation.In the present study,we identified a plant-specific SIMILAR TO RCD-ONE(SRO) protein family member,ZmSRO1e,involved in maize mesocotyl elongation.The expression of ZmSRO1e is strongly inhibited upon transfer from dark to white light.The loss-of-function zmsro1e mutant exhibited a dramatically shorter mesocotyl than the wild-type in both constant light and darkness,while overexpression of ZmSRO1e significantly promoted mesocotyl elongation,indicating that ZmSRO1e positively regulates mesocotyl elongation.We showed that ZmSRO1e physically interacted with Zmb ZIP61,an ortholog of Arabidopsis ELONGATED HYPOCOTYL 5(HY5) and showed a function similar to that of HY5 in regulating photomorphogenesis.We found that ZmSRO1e repressed the transcriptional activity of Zmb ZIP61 toward target genes involved in the regulation of cell expansion,such as ZmEXPB4 and ZmEXPB6,by interfering with the binding of ZmbZIP61 to the promoters of target genes.Our results provide a new understanding of the mechanism by which SRO regulates photomorphogenesis and highlight its potential application in deep sowing-resistant breeding.
