Rice(Oryza sativa) is a major crop that feeds billions of people, and its yield is strongly influenced by flowering time(heading date). Loss of RICE INDETERMINATE1(RID1) function causes plants not to flower;thus, RID1...Rice(Oryza sativa) is a major crop that feeds billions of people, and its yield is strongly influenced by flowering time(heading date). Loss of RICE INDETERMINATE1(RID1) function causes plants not to flower;thus, RID1 is considered a master switch among flowering-related genes. However, it remains unclear whether other proteins function together with RID1 to regulate rice floral transition.Here, we revealed that the chromatin accessibilityand H3 K9 ac, H3 K4 me3, and H3 K36 me3 levels at Heading date 3 a(Hd3 a) and RICE FLOWERING LOCUS T1(RFT1) loci were significantly reduced in rid1 mutants. Notably, RID1 interacted with SET DOMAIN GROUP PROTEIN 722(SDG722), a methyltransferase. We determined that SDG722 affects the global level of H3 K4 me2/3 and H3 K36 me2/3, and promotes flowering primarily through the Early heading date1-Hd3 a/RFT1 pathway. We further established that rice DELLA protein SLENDER RICE1(SLR1) interacted with RID1 to inhibit its transactivation activity, that SLR1 suppresses rice flowering, and that messenger RNA and protein levels of SLR1 gradually decrease with plant growth. Furthermore, SLR1 competed with SDG722 for interaction with RID1. Overall, our results establish that interplay between RID1, SLR1, and SDG722 feeds into rice flowering-time control.展开更多
Rice is one of the most important cereal crops in the world, and a substantial increase in grain yield is necessary for food security. However, high yields of semidwarf modern rice varieties are heavily dependent on t...Rice is one of the most important cereal crops in the world, and a substantial increase in grain yield is necessary for food security. However, high yields of semidwarf modern rice varieties are heavily dependent on the application of mineral nitrogenous fertilizer (Tilman et al., 2002;Sun et al., 2014). Nitrogen (N)-insensitive sponses associated with reduced N-use efficiency (NUE) is a major characteristic of the green revolution varieties (GRVs), in which the growth-inhibiting protein SLENDER RICE1 (SLR1) accumulates (Li et al., 2018). Unfortunately, increasing the level of N fertilizer use to reach the full yield potential of GRVs is subject to diminishing returns, quite apart from its deleterious effect on the environments (Rahn et al., 2009;Liu et al., 2015). Therefore, there is an urgent need to develop new rice GRVs that increase NUE while maintaining their high yields. Recently, several genes (e.g., DEP1, OsNRTl.lB, OsNRT2.3b, ARE1 and GRF4) responsible for improved NUE have been identified in rice (Sun et al.. 2014;Hu et al., 2015;Fan et al., 2016;Wang et al., 2018;Li et al., 2018). More importantly, boosting the activity of the transcription factor GRF4 overcomes the ability of SLR1 to prevent the GRF4-GIF1 interaction, which in turn promotes the coordinated expression of the genes involved in N assimilation and carbon fixation and consequently enhances the NUE of rice GRVs, thereby improving our ability to grow crops sustainably (Li et al., 2018). However, current understanding of the genetic basis for improving NUE remains at the level of identification of a number of quantitative trait loci (QTLs), without any understanding of the nature of the gene products.展开更多
The crosstalk between gibberellin(GA)and abscisic acid(ABA)signaling is crucial for balancing plant growth and adaption to environmental stress.Nevertheless,the molecular mechanism of their mutual antagonism still rem...The crosstalk between gibberellin(GA)and abscisic acid(ABA)signaling is crucial for balancing plant growth and adaption to environmental stress.Nevertheless,the molecular mechanism of their mutual antagonism still remains to be fully claried.In this study,we found that knockout of the rice NAC(NAM,ATAF1/2,CUC2)tran-scription factor gene OsNAC120 inhibits plant growth but enhances drought tolerance,whereas OsNAC120 overexpression produces the opposite results.Exogenous GA can rescue the semi-dwarf phenotype of osnac120 mutants,and further study showed that OsNAC120 promotes GA biosynthesis by transcriptionally activating the GA biosynthetic genes OsGA20ox1 and OsGA20ox3.The DELLA protein SLENDER RICE1(SLR1)interacts with OsNAC120 and impedes its transactivation ability,and GA treatment can remove the inhi-bition of transactivation activity caused by SLR1.On the other hand,OsNAC120 negatively regulates rice drought tolerance by repressing ABA-induced stomatal closure.Mechanistic investigation revealed that OsNAC120 inhibits ABA biosynthesis via transcriptional repression of the ABA biosynthetic genes OsNCED3 and OsNCED4.Rice OSMOTIC STRESS/ABA-ACTIVATED PROTEIN KINASE 9(OsSAPK9)physically interacts with OsNAC120 and mediates its phosphorylation,which results in OsNAC120 degradation.ABA treatment ac-celerates OsNAC120 degradation and reduces its transactivation activity.Together,our findings provide evidence that OsNAC120 plays critical roles in balancing GA-mediated growth and ABA-induced drought tolerance in rice.This research will help us to understand the mechanisms underlying the trade-off between plant growth and stress tolerance and to engineer stress-resistant,high-yielding crops.展开更多
Modern semi-dwarf rice varieties of the“Green Revolution”require a high supply of nitrogen(N)fertilizer to produce high yields.A better understanding of the interplay between N metabolism and plant developmental pro...Modern semi-dwarf rice varieties of the“Green Revolution”require a high supply of nitrogen(N)fertilizer to produce high yields.A better understanding of the interplay between N metabolism and plant developmental processes is required for improved N-use efficiency and agricultural sustainability.Here,we show that strigolactones(SLs)modulate root metabolic and developmental adaptations to low N availability for ensuring efficient uptake and translocation of available N.The key repressor DWARF 53(D53)of the SL signaling pathway interacts with the transcription factor GROWTH-REGULATING FACTOR 4(GRF4)and prevents GRF4 from binding to its target gene promoters.N limitation induces the accumulation of SLs,which in turn promotes SL-mediated degradation of D53,leading to the release of GRF4 and thus promoting the expression of genes associated with N metabolism.N limitation also induces degradation of the DELLA protein SLENDER RICE 1(SLR1)in an D14-and D53-dependent manner,effectively releasing GRF4 from competitive inhibition caused by SLR1.Collectively,our findings reveal a previously unrecognized mechanism underlying SL and gibberellin crosstalk in response to N availability,advancing our understanding of plant growth–metabolic coordination and facilitating the design of the strategies for improving N-use efficiency in high-yield crops.展开更多
基金funded by the National Natural Science Foundation of China(32070855 and 31821005)the National Key Research and Development Program of China(2016YFD0100903)。
文摘Rice(Oryza sativa) is a major crop that feeds billions of people, and its yield is strongly influenced by flowering time(heading date). Loss of RICE INDETERMINATE1(RID1) function causes plants not to flower;thus, RID1 is considered a master switch among flowering-related genes. However, it remains unclear whether other proteins function together with RID1 to regulate rice floral transition.Here, we revealed that the chromatin accessibilityand H3 K9 ac, H3 K4 me3, and H3 K36 me3 levels at Heading date 3 a(Hd3 a) and RICE FLOWERING LOCUS T1(RFT1) loci were significantly reduced in rid1 mutants. Notably, RID1 interacted with SET DOMAIN GROUP PROTEIN 722(SDG722), a methyltransferase. We determined that SDG722 affects the global level of H3 K4 me2/3 and H3 K36 me2/3, and promotes flowering primarily through the Early heading date1-Hd3 a/RFT1 pathway. We further established that rice DELLA protein SLENDER RICE1(SLR1) interacted with RID1 to inhibit its transactivation activity, that SLR1 suppresses rice flowering, and that messenger RNA and protein levels of SLR1 gradually decrease with plant growth. Furthermore, SLR1 competed with SDG722 for interaction with RID1. Overall, our results establish that interplay between RID1, SLR1, and SDG722 feeds into rice flowering-time control.
基金supported by grants from the National Natural Science Foundation of China (31830082)the National Key Research and Development Program of China (2016YFD0100401)the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB27010000)
文摘Rice is one of the most important cereal crops in the world, and a substantial increase in grain yield is necessary for food security. However, high yields of semidwarf modern rice varieties are heavily dependent on the application of mineral nitrogenous fertilizer (Tilman et al., 2002;Sun et al., 2014). Nitrogen (N)-insensitive sponses associated with reduced N-use efficiency (NUE) is a major characteristic of the green revolution varieties (GRVs), in which the growth-inhibiting protein SLENDER RICE1 (SLR1) accumulates (Li et al., 2018). Unfortunately, increasing the level of N fertilizer use to reach the full yield potential of GRVs is subject to diminishing returns, quite apart from its deleterious effect on the environments (Rahn et al., 2009;Liu et al., 2015). Therefore, there is an urgent need to develop new rice GRVs that increase NUE while maintaining their high yields. Recently, several genes (e.g., DEP1, OsNRTl.lB, OsNRT2.3b, ARE1 and GRF4) responsible for improved NUE have been identified in rice (Sun et al.. 2014;Hu et al., 2015;Fan et al., 2016;Wang et al., 2018;Li et al., 2018). More importantly, boosting the activity of the transcription factor GRF4 overcomes the ability of SLR1 to prevent the GRF4-GIF1 interaction, which in turn promotes the coordinated expression of the genes involved in N assimilation and carbon fixation and consequently enhances the NUE of rice GRVs, thereby improving our ability to grow crops sustainably (Li et al., 2018). However, current understanding of the genetic basis for improving NUE remains at the level of identification of a number of quantitative trait loci (QTLs), without any understanding of the nature of the gene products.
基金supported by the National Natural Science Foundation of China (32071985)the Chongqing Special Key Project for Technological Innovation and Application Development (CSTB2022TIAD-KPX0018,CSTB2022TIAD-KPX0016,CSTB2022TIAD-KPX0015).
文摘The crosstalk between gibberellin(GA)and abscisic acid(ABA)signaling is crucial for balancing plant growth and adaption to environmental stress.Nevertheless,the molecular mechanism of their mutual antagonism still remains to be fully claried.In this study,we found that knockout of the rice NAC(NAM,ATAF1/2,CUC2)tran-scription factor gene OsNAC120 inhibits plant growth but enhances drought tolerance,whereas OsNAC120 overexpression produces the opposite results.Exogenous GA can rescue the semi-dwarf phenotype of osnac120 mutants,and further study showed that OsNAC120 promotes GA biosynthesis by transcriptionally activating the GA biosynthetic genes OsGA20ox1 and OsGA20ox3.The DELLA protein SLENDER RICE1(SLR1)interacts with OsNAC120 and impedes its transactivation ability,and GA treatment can remove the inhi-bition of transactivation activity caused by SLR1.On the other hand,OsNAC120 negatively regulates rice drought tolerance by repressing ABA-induced stomatal closure.Mechanistic investigation revealed that OsNAC120 inhibits ABA biosynthesis via transcriptional repression of the ABA biosynthetic genes OsNCED3 and OsNCED4.Rice OSMOTIC STRESS/ABA-ACTIVATED PROTEIN KINASE 9(OsSAPK9)physically interacts with OsNAC120 and mediates its phosphorylation,which results in OsNAC120 degradation.ABA treatment ac-celerates OsNAC120 degradation and reduces its transactivation activity.Together,our findings provide evidence that OsNAC120 plays critical roles in balancing GA-mediated growth and ABA-induced drought tolerance in rice.This research will help us to understand the mechanisms underlying the trade-off between plant growth and stress tolerance and to engineer stress-resistant,high-yielding crops.
基金supported by the National Natural Science Foundation of China(grant nos.31830082,31972501,31672225,and 31601821)the National Key R&D Programme of China(2022YFD1200010-02 and 2022YFD1900702).
文摘Modern semi-dwarf rice varieties of the“Green Revolution”require a high supply of nitrogen(N)fertilizer to produce high yields.A better understanding of the interplay between N metabolism and plant developmental processes is required for improved N-use efficiency and agricultural sustainability.Here,we show that strigolactones(SLs)modulate root metabolic and developmental adaptations to low N availability for ensuring efficient uptake and translocation of available N.The key repressor DWARF 53(D53)of the SL signaling pathway interacts with the transcription factor GROWTH-REGULATING FACTOR 4(GRF4)and prevents GRF4 from binding to its target gene promoters.N limitation induces the accumulation of SLs,which in turn promotes SL-mediated degradation of D53,leading to the release of GRF4 and thus promoting the expression of genes associated with N metabolism.N limitation also induces degradation of the DELLA protein SLENDER RICE 1(SLR1)in an D14-and D53-dependent manner,effectively releasing GRF4 from competitive inhibition caused by SLR1.Collectively,our findings reveal a previously unrecognized mechanism underlying SL and gibberellin crosstalk in response to N availability,advancing our understanding of plant growth–metabolic coordination and facilitating the design of the strategies for improving N-use efficiency in high-yield crops.
