Increasing plant density has been recognized as an effective strategy for boosting maize yields over the past few decades.However,dense planting significantly reduces the internal light intensity and the red to far-re...Increasing plant density has been recognized as an effective strategy for boosting maize yields over the past few decades.However,dense planting significantly reduces the internal light intensity and the red to far-red(R:FR)light ratio in the canopy,which subsequently triggers shade avoidance responses(SAR)that limit further yield enhancements,particularly under high-density conditions.In this study,we identified double B-box containing protein DBB2,a member of the ZmBBX family that is rapidly induced by shade,as a crucial regulator of plant height and SAR.Disruption of DBB2 resulted in shorter internodes,reduced plant height,decreased cell elongation,and diminished sensitivity to shade in maize,effects that can be largely alleviated by external treatment with gibberellins(GA).Furthermore,we discovered that DBB2physically interacted with the transcription factor HY5,inhibiting its transcriptional activation of ZmGA2ox4,a gene encoding a GA2 oxidase that can deactivate GA.This interaction positively influences maize plant height through the GA pathway.Additionally,we found that the induction of ZmDBB2 by shade is mediated by the transcription factor PIF4.Interestingly,DBB2 then interacted with PIF4 to enhance the transcriptional activation of cell elongation-related genes,such as ZmEXPA1,thereby establishing a positive feedback loop promoting cell elongation under canopy shade conditions.Our findings highlight the critical role of BBX proteins in modulating plant height and SAR,presenting them as key genetic targets for developing maize varieties suited to high-density planting conditions.This study also provides new insights into the molecular mechanisms underlying SAR and offers potential strategies for the genetic improvement of maize plant architecture and grain yield.展开更多
In order to prevent or counteract shading,plants enact a complex set of growth and developmental adaptations when they sense a change in light quality caused by other plants in their vicinity.This shade avoidance resp...In order to prevent or counteract shading,plants enact a complex set of growth and developmental adaptations when they sense a change in light quality caused by other plants in their vicinity.This shade avoidance response（SAR）typically includes increased stem elongation at the expense of plant fitness and yield,making it an undesirable trait in an agricultural context.Manipulating the molecular factors involved in SAR can potentially improve productivity by increasing tolerance to higher planting density.However,most of the investigations of the molecular mechanism of SAR have been carried out in Arabidopsis thaliana,and it is presently unclear in how far results of these investigations apply to crop plants.In this review,current data on SAR in crop plants,especially from members of the Solanaceae and Poaceae families,are integrated with data from Arabidopsis,in order to identify the most promising targets for biotechnological approaches.Phytochromes,which detect the change in light caused by neighboring plants,and early signaling components can be targeted to increase plant productivity.However,they control various photomorphogenic processes not necessarily related to shade avoidance.Transcription factors involved in SAR signaling could be better targets to specifically enhance or suppress SAR.Knowledge integration from Arabidopsis and crop plants also indicates factors that could facilitate the control of specific aspects of SAR.Candidates are provided for the regulation of plant architecture,flowering induction and carbohydrate allocation.Yet to-be-elucidated factors that control SAR-dependent changes in biotic resistance and cell wall composition are pointed out.This review also includes an analysis of publicly available gene expression data for maize to augment the sparse molecular data available for this important species.展开更多
The effects of carbon nanoparticle(CNP)on rice variety Swarna(MTU7029)were investigated.CNP induced effects similar to shade avoidance response(SAR)of Arabidopsis,with increase in shoot length,root length,root number,...The effects of carbon nanoparticle(CNP)on rice variety Swarna(MTU7029)were investigated.CNP induced effects similar to shade avoidance response(SAR)of Arabidopsis,with increase in shoot length,root length,root number,cotyledon area,chlorophyll content and total sugar content in rice seedlings.In mature plants,CNP treatment resulted increase in plant height,number of productive tillers per plant,normalized difference vegetation index,quantum yield and root growth.A total of 320 mg of CNP per plant administered in four doses resulted in improved grain traits such as filled grain rate,100-grain weight,grain length/width ratio,hulling rate,milling rate and head rice recovery.Seeds from the CNP-treated plants showed increase in amylose,starch and soluble sugar contents compared to controls.Strikingly,CNP treatment showed an average of 17.5%increase in yield per plant.Upon investigation to the molecular mechanism behind CNP induction of SAR,a significant downregulation of phytochrome B transcript was found.Decrease in perception of red wavelengths led to responses similar to SAR.Increase in plant’s internal temperature by 0.5ºC±0.1ºC was recorded after CNP treatment.We suggest that the internalized CNP aggregates may serve to absorb extra photons thereby increasing the internal temperature of plants.Phytochrome B accounts the hike in internal temperature and initiates a feed-back reduction of its own transcription.We suggest that moderate SAR is beneficial for rice plants to improve agronomic traits and yield.It presents a potential non-transgenic method for improving rice yield by CNP treatment.展开更多
Summary A better understanding of shade avoidance syndrome （SAS） is an urgent need because of its effect on energy reallocation. Leverage-related mechanism in crops is of potential economic interest for agricultural...Summary A better understanding of shade avoidance syndrome （SAS） is an urgent need because of its effect on energy reallocation. Leverage-related mechanism in crops is of potential economic interest for agricultural applications. Here we report the SAS phenotype at tissue level rice seedlings. Tissue-specific RNA-sequencing indicates auxin plays different roles between coleoptile and the first leaf. Phenotypes of wild type treated by gibberellin and brassinosteroid biosynthesis inhibitors and of related mutants suggest these two hormones positively regulate SAS. Our work reveals the diversity of hormone responses in different organs and different species in shade conditions.展开更多
基金supported by the National Natural Science Foundation of China(32270263 to G.L.,32400297 to Q.S.,32372198 to F.K.)the Shandong Provincial Natural Science Foundation(ZR2022QC095,ZR2022MC019)。
文摘Increasing plant density has been recognized as an effective strategy for boosting maize yields over the past few decades.However,dense planting significantly reduces the internal light intensity and the red to far-red(R:FR)light ratio in the canopy,which subsequently triggers shade avoidance responses(SAR)that limit further yield enhancements,particularly under high-density conditions.In this study,we identified double B-box containing protein DBB2,a member of the ZmBBX family that is rapidly induced by shade,as a crucial regulator of plant height and SAR.Disruption of DBB2 resulted in shorter internodes,reduced plant height,decreased cell elongation,and diminished sensitivity to shade in maize,effects that can be largely alleviated by external treatment with gibberellins(GA).Furthermore,we discovered that DBB2physically interacted with the transcription factor HY5,inhibiting its transcriptional activation of ZmGA2ox4,a gene encoding a GA2 oxidase that can deactivate GA.This interaction positively influences maize plant height through the GA pathway.Additionally,we found that the induction of ZmDBB2 by shade is mediated by the transcription factor PIF4.Interestingly,DBB2 then interacted with PIF4 to enhance the transcriptional activation of cell elongation-related genes,such as ZmEXPA1,thereby establishing a positive feedback loop promoting cell elongation under canopy shade conditions.Our findings highlight the critical role of BBX proteins in modulating plant height and SAR,presenting them as key genetic targets for developing maize varieties suited to high-density planting conditions.This study also provides new insights into the molecular mechanisms underlying SAR and offers potential strategies for the genetic improvement of maize plant architecture and grain yield.
基金supported by the funding provided to Dr. Johannes Liesche by Northwest A&F University, China
文摘In order to prevent or counteract shading,plants enact a complex set of growth and developmental adaptations when they sense a change in light quality caused by other plants in their vicinity.This shade avoidance response（SAR）typically includes increased stem elongation at the expense of plant fitness and yield,making it an undesirable trait in an agricultural context.Manipulating the molecular factors involved in SAR can potentially improve productivity by increasing tolerance to higher planting density.However,most of the investigations of the molecular mechanism of SAR have been carried out in Arabidopsis thaliana,and it is presently unclear in how far results of these investigations apply to crop plants.In this review,current data on SAR in crop plants,especially from members of the Solanaceae and Poaceae families,are integrated with data from Arabidopsis,in order to identify the most promising targets for biotechnological approaches.Phytochromes,which detect the change in light caused by neighboring plants,and early signaling components can be targeted to increase plant productivity.However,they control various photomorphogenic processes not necessarily related to shade avoidance.Transcription factors involved in SAR signaling could be better targets to specifically enhance or suppress SAR.Knowledge integration from Arabidopsis and crop plants also indicates factors that could facilitate the control of specific aspects of SAR.Candidates are provided for the regulation of plant architecture,flowering induction and carbohydrate allocation.Yet to-be-elucidated factors that control SAR-dependent changes in biotic resistance and cell wall composition are pointed out.This review also includes an analysis of publicly available gene expression data for maize to augment the sparse molecular data available for this important species.
基金supported by the Department of Science and Technology,Women Scientist Scheme-A in India(Grant No.SR/WOS-A/LS-369/2018)Science Engineering Research Board,Young Scientist Start-Up Grant in India(Grant No.YSS-2015-000659)+1 种基金Department of Science and Technology,Science Engineering Research Board,India(Grant No.EMR/2014/000533)Department of Atomic Energy,National Institute of Science Education and Research in India.
文摘The effects of carbon nanoparticle(CNP)on rice variety Swarna(MTU7029)were investigated.CNP induced effects similar to shade avoidance response(SAR)of Arabidopsis,with increase in shoot length,root length,root number,cotyledon area,chlorophyll content and total sugar content in rice seedlings.In mature plants,CNP treatment resulted increase in plant height,number of productive tillers per plant,normalized difference vegetation index,quantum yield and root growth.A total of 320 mg of CNP per plant administered in four doses resulted in improved grain traits such as filled grain rate,100-grain weight,grain length/width ratio,hulling rate,milling rate and head rice recovery.Seeds from the CNP-treated plants showed increase in amylose,starch and soluble sugar contents compared to controls.Strikingly,CNP treatment showed an average of 17.5%increase in yield per plant.Upon investigation to the molecular mechanism behind CNP induction of SAR,a significant downregulation of phytochrome B transcript was found.Decrease in perception of red wavelengths led to responses similar to SAR.Increase in plant’s internal temperature by 0.5ºC±0.1ºC was recorded after CNP treatment.We suggest that the internalized CNP aggregates may serve to absorb extra photons thereby increasing the internal temperature of plants.Phytochrome B accounts the hike in internal temperature and initiates a feed-back reduction of its own transcription.We suggest that moderate SAR is beneficial for rice plants to improve agronomic traits and yield.It presents a potential non-transgenic method for improving rice yield by CNP treatment.
基金supported by National Natural Science Foundation of China Grants 31470374the Shanghai Pujiang Talent Program (14PJ1400800)a start-up grant from Fudan University to L.L
文摘Summary A better understanding of shade avoidance syndrome （SAS） is an urgent need because of its effect on energy reallocation. Leverage-related mechanism in crops is of potential economic interest for agricultural applications. Here we report the SAS phenotype at tissue level rice seedlings. Tissue-specific RNA-sequencing indicates auxin plays different roles between coleoptile and the first leaf. Phenotypes of wild type treated by gibberellin and brassinosteroid biosynthesis inhibitors and of related mutants suggest these two hormones positively regulate SAS. Our work reveals the diversity of hormone responses in different organs and different species in shade conditions.
