Homeodomain-leucine zipper(HD-Zip)transcription factors are only present in higher plants and are involved in plant development and stress responses.However,our understanding of their participation in the fruit ripeni...Homeodomain-leucine zipper(HD-Zip)transcription factors are only present in higher plants and are involved in plant development and stress responses.However,our understanding of their participation in the fruit ripening of economical plants,such as tomato(Solanum lycopersicum),remains largely unclear.Here,we report that VAHOX1,a member of the tomato HD-Zip I subfamily,was expressed in all tissues,was highly expressed in breaker+4 fruits,and could be induced by ethylene.RNAi repression of VAHOX1(VAHOX1-RNAi)resulted in accelerated fruit ripening,enhanced sensitivity to ethylene,and increased total carotenoid content and ethylene production.Conversely,VAHOX1 overexpression(VAHOX1-OE)in tomato had the opposite effect.RNA-Seq results showed that altering VAHOX1 expression affected the transcript accumulation of a series of genes involved in ethylene biosynthesis and signal transduction and cell wall modification.Additionally,a dual-luciferase reporter assay,histochemical analysis of GUS activity and a yeast one-hybrid(Y1H)assay revealed that VAHOX1 could activate the expression of AP2a.Our findings may expand our knowledge about the physiological functions of HD-Zip transcription factors in tomato and highlight the diversities of transcriptional regulation during the fruit ripening process.展开更多
The OVATE gene was initially identified in tomato and serves as a key regulator of fruit shape.There are 31 OFP members in the tomato genome.However,their roles in tomato growth and reproductive development are largel...The OVATE gene was initially identified in tomato and serves as a key regulator of fruit shape.There are 31 OFP members in the tomato genome.However,their roles in tomato growth and reproductive development are largely unknown.Here,we cloned the OFP transcription factor SlOFP20.Tomato plants overexpressing SlOFP20 displayed several phenotypic defects,including an altered floral architecture and fruit shape and reduced male fertility.SlOFP20 overexpression altered the expression levels of some brassinosteroid(BR)-associated genes,implying that SlOFP20 may play a negative role in the BR response,similar to its ortholog OsOFP19 in rice.Moreover,the transcript accumulation of gibberellin(GA)-related genes was significantly affected in the transgenic lines.SlOFP20 may play an important role in the crosstalk between BR and GA.The pollen germination assay suggested that the pollen germination rate of SlOFP20-OE plants was distinctly lower than that of WT plants.In addition,the tomato pollen-associated genes SlCRK1,SlPMEI,LePRK3,SlPRALF,and LAT52 were all suppressed in the transgenic lines.Our data imply that SlOFP20 may affect floral organ and pollen development by modulating BR and GA signaling in tomato.展开更多
基金The project was supported by the National Natural Science Foun-dation of China(no.31872121)the Natural Science Founda-tion of Chongqing,China(csts2019jcyj-msxmX0094,cstc2019jcyj-msxmX0361).
文摘Homeodomain-leucine zipper(HD-Zip)transcription factors are only present in higher plants and are involved in plant development and stress responses.However,our understanding of their participation in the fruit ripening of economical plants,such as tomato(Solanum lycopersicum),remains largely unclear.Here,we report that VAHOX1,a member of the tomato HD-Zip I subfamily,was expressed in all tissues,was highly expressed in breaker+4 fruits,and could be induced by ethylene.RNAi repression of VAHOX1(VAHOX1-RNAi)resulted in accelerated fruit ripening,enhanced sensitivity to ethylene,and increased total carotenoid content and ethylene production.Conversely,VAHOX1 overexpression(VAHOX1-OE)in tomato had the opposite effect.RNA-Seq results showed that altering VAHOX1 expression affected the transcript accumulation of a series of genes involved in ethylene biosynthesis and signal transduction and cell wall modification.Additionally,a dual-luciferase reporter assay,histochemical analysis of GUS activity and a yeast one-hybrid(Y1H)assay revealed that VAHOX1 could activate the expression of AP2a.Our findings may expand our knowledge about the physiological functions of HD-Zip transcription factors in tomato and highlight the diversities of transcriptional regulation during the fruit ripening process.
基金supported by the National Natural Science Foundation of China(no.31572129)the Technology System of National Bulk Vegetable Industry-Eggplant Breeding Position(CARS-25-A-06).
文摘The OVATE gene was initially identified in tomato and serves as a key regulator of fruit shape.There are 31 OFP members in the tomato genome.However,their roles in tomato growth and reproductive development are largely unknown.Here,we cloned the OFP transcription factor SlOFP20.Tomato plants overexpressing SlOFP20 displayed several phenotypic defects,including an altered floral architecture and fruit shape and reduced male fertility.SlOFP20 overexpression altered the expression levels of some brassinosteroid(BR)-associated genes,implying that SlOFP20 may play a negative role in the BR response,similar to its ortholog OsOFP19 in rice.Moreover,the transcript accumulation of gibberellin(GA)-related genes was significantly affected in the transgenic lines.SlOFP20 may play an important role in the crosstalk between BR and GA.The pollen germination assay suggested that the pollen germination rate of SlOFP20-OE plants was distinctly lower than that of WT plants.In addition,the tomato pollen-associated genes SlCRK1,SlPMEI,LePRK3,SlPRALF,and LAT52 were all suppressed in the transgenic lines.Our data imply that SlOFP20 may affect floral organ and pollen development by modulating BR and GA signaling in tomato.
