Shoot branching is an important crop agronomic trait that directly affects plant architecture and crop productivity.Although phytochrome B(phy B),BRANCHED1(BRC1),and abscisic acid(ABA) mediate axillary bud outgrowth,i...Shoot branching is an important crop agronomic trait that directly affects plant architecture and crop productivity.Although phytochrome B(phy B),BRANCHED1(BRC1),and abscisic acid(ABA) mediate axillary bud outgrowth,it is unknown if there is any integrating factor among them in the Plantae.We report that mutation of Csphy B or inactivation of Csphy B by shade inhibits lateral bud outgrowth in cucumber.Cucumber PHYTOCHROME INTERACTING FACTOR 4(Cs PIF4) interacts with Csphy B and directly binds to the promoter of CsBRC1 to activate CsBRC1 expression.CsBRC1 also directly promotes the expression of ABA biosynthesis gene 9-CIS-EPOXICAROTENOID DIOXIGENASE 3(CsNCED3).Functional disruption of Cs PIF4 decreased expression of CsBRC1 and CsNCED3,reduced ABA accumulation,and increased bud outgrowth in cucumber.Csnced3 mutants had reduced ABA levels and increased lateral bud outgrowth.These results suggest that a regulatory network involving Csphy B-Cs PIF4-CsBRC1 exists that integrates light signaling and ABA biosynthesis to modulate bud outgrowth.This provides a strategy to manipulate branch numbers in crop breeding to realize ideal branching characteristics to maximize yield.展开更多
基金supported by grants from the National Natural Science Foundation of China(32372699, 32025033, and 32102387)Key R&D Program of Shandong Province,China (2024LZGCQY006)S&T Program of Hebei (22326308D)。
文摘Shoot branching is an important crop agronomic trait that directly affects plant architecture and crop productivity.Although phytochrome B(phy B),BRANCHED1(BRC1),and abscisic acid(ABA) mediate axillary bud outgrowth,it is unknown if there is any integrating factor among them in the Plantae.We report that mutation of Csphy B or inactivation of Csphy B by shade inhibits lateral bud outgrowth in cucumber.Cucumber PHYTOCHROME INTERACTING FACTOR 4(Cs PIF4) interacts with Csphy B and directly binds to the promoter of CsBRC1 to activate CsBRC1 expression.CsBRC1 also directly promotes the expression of ABA biosynthesis gene 9-CIS-EPOXICAROTENOID DIOXIGENASE 3(CsNCED3).Functional disruption of Cs PIF4 decreased expression of CsBRC1 and CsNCED3,reduced ABA accumulation,and increased bud outgrowth in cucumber.Csnced3 mutants had reduced ABA levels and increased lateral bud outgrowth.These results suggest that a regulatory network involving Csphy B-Cs PIF4-CsBRC1 exists that integrates light signaling and ABA biosynthesis to modulate bud outgrowth.This provides a strategy to manipulate branch numbers in crop breeding to realize ideal branching characteristics to maximize yield.
