Short basal internodes are important for lodging resistance of rice(Oryza sativa L.).Several canopy indices affect the elongation of basal internodes,but uncertainty as to the key factors determining elongation of bas...Short basal internodes are important for lodging resistance of rice(Oryza sativa L.).Several canopy indices affect the elongation of basal internodes,but uncertainty as to the key factors determining elongation of basal internodes persists.The objectives of this study were(1)to identify key factors affecting the elongation of basal internodes and(2)to establish a quantitative relationship between basal internode length and canopy indices.An inbred rice cultivar,Yinjingruanzhan,was grown in two split-plot field experiments with three N rates(0,75,and 150 kg N ha−1 in early season and 0,90,and 180 kg N ha−1 in late season)as main plots,three seedling densities(16.7,75.0,and 187.5 seedlings m−2)as subplots,and three replications in the 2015 early and late seasons in Guangzhou,China.Light intensity at base of canopy(Lb),light quality as determined from red/far-red light ratio(R/FR),light transmission ratio(LTR),leaf area index(LAI),leaf N concentration(NLV)and final length of second internode(counted from soil surface upward)(FIL)were recorded.Higher N rate and seedling density resulted in significantly longer FIL.FIL was negatively correlated with Lb,LTR,and R/FR(P<0.01)and positively correlated with LAI(P<0.01),but not correlated with NLV(P>0.05).Stepwise linear regression analysis showed that FIL was strongly associated with Lb and LAI(R2=0.82).Heavy N application to pot-grown rice at the beginning of first internode elongation did not change FIL.We conclude that FIL is determined mainly by Lb and LAI at jointing stage.NLV has no direct effect on the elongation of basal internodes.N application indirectly affects FIL by changing LAI and light conditions in the rice canopy.Reducing LAI and improving canopy light transmission at jointing stage can shorten the basal internodes and increase the lodging resistance of rice.展开更多
In angiosperms, low red (R)/far-red (FR) ratio light increases gibberellin (GA) levels. GA signaling in conifer seedlings requires FR to promote shoot elongation and reduce the inhibition of shoot elongation induced b...In angiosperms, low red (R)/far-red (FR) ratio light increases gibberellin (GA) levels. GA signaling in conifer seedlings requires FR to promote shoot elongation and reduce the inhibition of shoot elongation induced by paclobutrazol (PAC), yet the effects of far-red light in inducing shoot elongation in the presence or absence of PAC is poorly understood. In this study, transcriptomic and proteomic analyses was used to examine the molecular mechanism of FR regulation of shoot elongation in Chinese pine (Pinus tabuliformis Carr.) seedlings in the presence of PAC. Four treatments were compared: white light + water (WW), FR + water (RW), white light + PAC (WP), and FR + PAC (RP), and 1436 differentially expressed genes (DEGs) and 450 differentially expressed proteins (DEPs) were identified in RW_WW (RW contrast WW), and 1862 DEGs and 481 DEPs in RP_WP (RP contrast WP). Metabolic and signal transduction pathway analyses of DEGs and DEPs in RW_WW and RP_WP, indicated that the former required more energy than the latter. Moreover, gibberellic acid, auxin, and brassinolide are equally important in RW_WW and RP_WP for shoot elongation, except for the ethylene pathway. Amino acid metabolism and cell wall organization were significantly enriched in RW_WW and RP_WP, respectively. In summary, RW_WW and RP_WP had different effects in secondary metabolism, energy metabolism, amino acid metabolism, cell wall organization, and hormone response. These results provide an important theoretical and reference basis for studying the regulatory effect of low R/FR and PAC in conifer shoot elongation.展开更多
基金supported by the Natural Science Foundation of Guangdong Province,China(S2012020011043)the National High Technology Research and Development Program of China(2014AA10A605)+2 种基金the Special Fund for Agro-scientific Research in the Public Interest(201503106)Modern Agriculture Industry Technology System for Rice in Guangdong Province(2016LM1066,2017LM1066,2018LM1066)the Swiss Agency for Development and Cooperation through its funding of “Closing Rice Yield Gaps in Asia” Project(CORIGAP)
文摘Short basal internodes are important for lodging resistance of rice(Oryza sativa L.).Several canopy indices affect the elongation of basal internodes,but uncertainty as to the key factors determining elongation of basal internodes persists.The objectives of this study were(1)to identify key factors affecting the elongation of basal internodes and(2)to establish a quantitative relationship between basal internode length and canopy indices.An inbred rice cultivar,Yinjingruanzhan,was grown in two split-plot field experiments with three N rates(0,75,and 150 kg N ha−1 in early season and 0,90,and 180 kg N ha−1 in late season)as main plots,three seedling densities(16.7,75.0,and 187.5 seedlings m−2)as subplots,and three replications in the 2015 early and late seasons in Guangzhou,China.Light intensity at base of canopy(Lb),light quality as determined from red/far-red light ratio(R/FR),light transmission ratio(LTR),leaf area index(LAI),leaf N concentration(NLV)and final length of second internode(counted from soil surface upward)(FIL)were recorded.Higher N rate and seedling density resulted in significantly longer FIL.FIL was negatively correlated with Lb,LTR,and R/FR(P<0.01)and positively correlated with LAI(P<0.01),but not correlated with NLV(P>0.05).Stepwise linear regression analysis showed that FIL was strongly associated with Lb and LAI(R2=0.82).Heavy N application to pot-grown rice at the beginning of first internode elongation did not change FIL.We conclude that FIL is determined mainly by Lb and LAI at jointing stage.NLV has no direct effect on the elongation of basal internodes.N application indirectly affects FIL by changing LAI and light conditions in the rice canopy.Reducing LAI and improving canopy light transmission at jointing stage can shorten the basal internodes and increase the lodging resistance of rice.
基金This work was supported by the National Natural Science Foundation of China(31770713)Biosafety and Genetic Resources Management Project of State Forestry and Grassland Administration(KJZXSA202030).
文摘In angiosperms, low red (R)/far-red (FR) ratio light increases gibberellin (GA) levels. GA signaling in conifer seedlings requires FR to promote shoot elongation and reduce the inhibition of shoot elongation induced by paclobutrazol (PAC), yet the effects of far-red light in inducing shoot elongation in the presence or absence of PAC is poorly understood. In this study, transcriptomic and proteomic analyses was used to examine the molecular mechanism of FR regulation of shoot elongation in Chinese pine (Pinus tabuliformis Carr.) seedlings in the presence of PAC. Four treatments were compared: white light + water (WW), FR + water (RW), white light + PAC (WP), and FR + PAC (RP), and 1436 differentially expressed genes (DEGs) and 450 differentially expressed proteins (DEPs) were identified in RW_WW (RW contrast WW), and 1862 DEGs and 481 DEPs in RP_WP (RP contrast WP). Metabolic and signal transduction pathway analyses of DEGs and DEPs in RW_WW and RP_WP, indicated that the former required more energy than the latter. Moreover, gibberellic acid, auxin, and brassinolide are equally important in RW_WW and RP_WP for shoot elongation, except for the ethylene pathway. Amino acid metabolism and cell wall organization were significantly enriched in RW_WW and RP_WP, respectively. In summary, RW_WW and RP_WP had different effects in secondary metabolism, energy metabolism, amino acid metabolism, cell wall organization, and hormone response. These results provide an important theoretical and reference basis for studying the regulatory effect of low R/FR and PAC in conifer shoot elongation.
