Grain shape and size both determine grain weight and therefore crop yield. However, the molecular mechanisms controlling grain shape and size are still largely unknown. Here, we isolated a rice mutant, beak-shaped gra...Grain shape and size both determine grain weight and therefore crop yield. However, the molecular mechanisms controlling grain shape and size are still largely unknown. Here, we isolated a rice mutant, beak-shaped grain1 （bsgl）, which produced beak-shaped grains of decreased width, thickness and weight with a loosely interlocked lemma and palea that were unable to close tightly. Starch granules were also irregularly packaged in the bsgl grains. Consistent with the lemma and palea shapes, the outer parenchyma cell layers of these bsgl tissues developed fewer cells with decreased size. Map-based cloning revealed that BSG1 encoded a DUF640 domain protein, TRIANGULAR HULL 1, of unknown function. Quantitative PCR and GUS fusion reporter assays showed that BSG1 was expressed mainly in the young panicle and elongating stem. The BSG1 mutation affected the expression of genes potentially involved in the cell cycle and GW2, an important regulator of grain size in rice. Our results suggest that BSG1 determines grain shape and size probably by modifying cell division and expansion in the grain hull.展开更多
How to evaluate time-domain Green function and its gradients efficiently is the key problem to analyze ship hydrodynamics in time domain. Based on the Bessel function, an Ordinary Differential Equation （ODE） was der...How to evaluate time-domain Green function and its gradients efficiently is the key problem to analyze ship hydrodynamics in time domain. Based on the Bessel function, an Ordinary Differential Equation （ODE） was derived for time-domain Green function and its gradients in this paper. A new efficient calculation method based on solving ODE is proposed. It has been demonstrated by the numerical calculation that this method can improve the precision of the time-domain Green function. Numeiical research indicates that it is efficient to solve the hydrodynamic problems.展开更多
Manual fruit thinning(MFT)in fruit trees has been previously shown to increase fruit size and enhance fruit quality,but the effect of MFT on Ponkan(Citrus reticulata Blanco)and the underlying mechanisms remain poorly ...Manual fruit thinning(MFT)in fruit trees has been previously shown to increase fruit size and enhance fruit quality,but the effect of MFT on Ponkan(Citrus reticulata Blanco)and the underlying mechanisms remain poorly understood.In this study,efforts were made to elucidate how MFT influences the fruit quality of Ponkan.The results showed that MFT substantially increased fruit size and elevated fruit total soluble solids in comparison with the fruit from the unthinned trees(used as control).Expression analyses demonstrated that m RNA abundance of three important sugar transporter genes,including CrSUT1,CrSTP1 and CrTMT1,was evidently elevated in the flesh of thinned fruit when compared with those of the control.In addition,MFT prominently up-regulated the transcript levels of various auxin and gibberellin(GA)biosynthesis and signaling genes,including CrYUC6,CrAUX/IAA,CrGA20ox1 and CrGA3ox1.Concurrently,the contents of endogenous IAA and GA3,measured at 90 d after fruit thinning,were notably elevated in the fruit from trees with the thinning treatment relative to the control,although no difference was detected in the two groups before the thinning manipulation.Taken together,these results indicate that manual fruit thinning could greatly improve fruit quality,which may be attributed to promoting fruit expansion due to the increased auxin levels and expediting sugar accumulation through the up-regulation of sugar transporter genes.展开更多
基金supported by grants from the Chinese Academy of Sciences (KSCX2-EW-N-01)the National Natural Science Foundation of China (31100142,31071207)
文摘Grain shape and size both determine grain weight and therefore crop yield. However, the molecular mechanisms controlling grain shape and size are still largely unknown. Here, we isolated a rice mutant, beak-shaped grain1 （bsgl）, which produced beak-shaped grains of decreased width, thickness and weight with a loosely interlocked lemma and palea that were unable to close tightly. Starch granules were also irregularly packaged in the bsgl grains. Consistent with the lemma and palea shapes, the outer parenchyma cell layers of these bsgl tissues developed fewer cells with decreased size. Map-based cloning revealed that BSG1 encoded a DUF640 domain protein, TRIANGULAR HULL 1, of unknown function. Quantitative PCR and GUS fusion reporter assays showed that BSG1 was expressed mainly in the young panicle and elongating stem. The BSG1 mutation affected the expression of genes potentially involved in the cell cycle and GW2, an important regulator of grain size in rice. Our results suggest that BSG1 determines grain shape and size probably by modifying cell division and expansion in the grain hull.
基金This work was financially supported by Key Program of the National Natural Science Foundation of China(No.50639020)the National High Technology Research and Development Program of China(863Program)(No.2006AA09Z332)
文摘How to evaluate time-domain Green function and its gradients efficiently is the key problem to analyze ship hydrodynamics in time domain. Based on the Bessel function, an Ordinary Differential Equation （ODE） was derived for time-domain Green function and its gradients in this paper. A new efficient calculation method based on solving ODE is proposed. It has been demonstrated by the numerical calculation that this method can improve the precision of the time-domain Green function. Numeiical research indicates that it is efficient to solve the hydrodynamic problems.
基金supported by the Hubei Provincial Agriculture Research System,Chinathe Special Program for Technology Innovation of Hubei Province,China(2020BBA036)the Hubei Provincial Agricultural Science and Technology Innovation,China。
文摘Manual fruit thinning(MFT)in fruit trees has been previously shown to increase fruit size and enhance fruit quality,but the effect of MFT on Ponkan(Citrus reticulata Blanco)and the underlying mechanisms remain poorly understood.In this study,efforts were made to elucidate how MFT influences the fruit quality of Ponkan.The results showed that MFT substantially increased fruit size and elevated fruit total soluble solids in comparison with the fruit from the unthinned trees(used as control).Expression analyses demonstrated that m RNA abundance of three important sugar transporter genes,including CrSUT1,CrSTP1 and CrTMT1,was evidently elevated in the flesh of thinned fruit when compared with those of the control.In addition,MFT prominently up-regulated the transcript levels of various auxin and gibberellin(GA)biosynthesis and signaling genes,including CrYUC6,CrAUX/IAA,CrGA20ox1 and CrGA3ox1.Concurrently,the contents of endogenous IAA and GA3,measured at 90 d after fruit thinning,were notably elevated in the fruit from trees with the thinning treatment relative to the control,although no difference was detected in the two groups before the thinning manipulation.Taken together,these results indicate that manual fruit thinning could greatly improve fruit quality,which may be attributed to promoting fruit expansion due to the increased auxin levels and expediting sugar accumulation through the up-regulation of sugar transporter genes.
