近年来,全球低温极端气候频发,对水稻生产带来严重的影响。低温严重限制了水稻种植区域的扩大。因此,鉴定克隆水稻低温发育相关基因,阐明其分子机理,可为水稻低温分子育种奠定理论基础。本研究从水稻日本晴化学诱变突变体库筛选鉴定到1...近年来,全球低温极端气候频发,对水稻生产带来严重的影响。低温严重限制了水稻种植区域的扩大。因此,鉴定克隆水稻低温发育相关基因,阐明其分子机理,可为水稻低温分子育种奠定理论基础。本研究从水稻日本晴化学诱变突变体库筛选鉴定到1个低温叶片白化的突变体lta1(Low temperature albinism1)。相比野生型,在20℃生长条件下,突变体lta1叶片白化,叶绿素含量显著降低,叶绿体结构发育异常;在30℃生长条件下,突变体lta1与野生型生长无显著差异。通过图位克隆将突变基因lta1定位在第3号染色体短臂InDel标记LTA1-3与LTA1-7之间,物理距离为132 kb。基于水稻基因表达数据库,在132 kb区间内有17个候选基因,其中有6个候选基因翻译的蛋白可能定位于叶绿体。实时荧光定量PCR结果表明多数叶绿体编码基因的表达在突变体中受到显著抑制,而多数叶绿素合成相关基因的表达未发生显著变化。本研究结果为进一步克隆LTA1基因与揭示水稻低温下叶绿体发育的机理提供可能。展开更多
Plant chlorophyll biosynthesis and chloroplast development are two complex processes that are regulated by exogenous and endogenous factors. In this study, we identified OsDXR, a gene encoding a reductoisomerase that ...Plant chlorophyll biosynthesis and chloroplast development are two complex processes that are regulated by exogenous and endogenous factors. In this study, we identified OsDXR, a gene encoding a reductoisomerase that positively regulates chlorophyll biosynthesis and chloroplast development in rice. OsDXR knock-out lines displayed the albino phenotype and could not complete the whole life cycle process. OsDXR was highly expressed in rice leaves, and subcellular localization indicated that OsDXR is a chloroplast protein. Many genes involved in chlorophyll biosynthesis and chloroplast development were differentially expressed in the OsDXR knock-out lines compared to the wild type.Moreover, we found that the RNA editing efficiencies of ndhA-1019 and rpl2-1 were significantly reduced in the OsDXR knock-out lines. Furthermore, OsDXR interacted with the RNA editing factor OsMORF1 in a yeast two-hybrid screen and bimolecular fluorescence complementation assay. Finally, disruption of the plastidial 2-C-methyl-derythritol-4-phosphate pathway resulted in defects in chloroplast development and the RNA editing of chloroplast genes.展开更多
The accumulation dynamics of kernel components for spikelets at different positions within a rice panicle were investigated during grain filling to understand the physiological reasons for the variation of grain quali...The accumulation dynamics of kernel components for spikelets at different positions within a rice panicle were investigated during grain filling to understand the physiological reasons for the variation of grain quality.Two rice cultivars,Yangdao 6 （indica） and Yangjing 9538 （japonica）,were field-grown,and the grain filling characters and contents of starch,soluble sugar,and protein of the spikelets at different positions were studied.There were significant differences in matter accumulation among spikelets at different positions during grain filling.The early-flowering spikelets presented dominance over the late-flowering spikelets in initial time and initial rate of accumulation.At the initial and mid filling stages,the contents and the rates of starch and amylose accumulation in spikelets decreased with the flowering sequence,but soluble sugar content （SSC） exhibited the opposite trend.The difference in SSC among the spikelets of Yangjing 9538 was greater than that of Yangdao 6,but amylose content in mature spikelets showed no obvious relationship to their flowering sequence.The crude protein content （CPC） of early-flowering spikelets decreased more rapidly than that of late-flowering ones at the initial filling stage,and CPC in the spikelets on the secondary branch was higher than that on the primary branch,but CPC in early-flowering ones was lower than that in late-flowering across the whole grain filling period.Grain water content （GWC） of early-flowering spikelets decreased more rapidly than that of late-flowering spikelets on the same branch at the initial and mid filling stages,especially for the top grain on each primary branch.The results suggested that poor grain filling of late-flowering spikelets may be attributed to their low biological activity rather than carbohydrate supply limitation.展开更多
文摘近年来,全球低温极端气候频发,对水稻生产带来严重的影响。低温严重限制了水稻种植区域的扩大。因此,鉴定克隆水稻低温发育相关基因,阐明其分子机理,可为水稻低温分子育种奠定理论基础。本研究从水稻日本晴化学诱变突变体库筛选鉴定到1个低温叶片白化的突变体lta1(Low temperature albinism1)。相比野生型,在20℃生长条件下,突变体lta1叶片白化,叶绿素含量显著降低,叶绿体结构发育异常;在30℃生长条件下,突变体lta1与野生型生长无显著差异。通过图位克隆将突变基因lta1定位在第3号染色体短臂InDel标记LTA1-3与LTA1-7之间,物理距离为132 kb。基于水稻基因表达数据库,在132 kb区间内有17个候选基因,其中有6个候选基因翻译的蛋白可能定位于叶绿体。实时荧光定量PCR结果表明多数叶绿体编码基因的表达在突变体中受到显著抑制,而多数叶绿素合成相关基因的表达未发生显著变化。本研究结果为进一步克隆LTA1基因与揭示水稻低温下叶绿体发育的机理提供可能。
基金supported by the Program for Subsidized Project of Suzhou Academy of Agricultural Sciences,China(20028)the Science and Technology Foundation of Suzhou(SNG2020048)+3 种基金the Huaishang Talents,China,the National Natural Science Foundation of China(32070345)the Huai’an Academy of Agricultural Sciences Initiation and Development of Scientific Research Fund for High-level Introduced Talents,China(0062019016B)the Six Talents Summit Project of Jiangsu Province,China(NY-129)the Natural Science Foundation of Jiangsu Province,China(BK20190239 and BK20180107)。
文摘Plant chlorophyll biosynthesis and chloroplast development are two complex processes that are regulated by exogenous and endogenous factors. In this study, we identified OsDXR, a gene encoding a reductoisomerase that positively regulates chlorophyll biosynthesis and chloroplast development in rice. OsDXR knock-out lines displayed the albino phenotype and could not complete the whole life cycle process. OsDXR was highly expressed in rice leaves, and subcellular localization indicated that OsDXR is a chloroplast protein. Many genes involved in chlorophyll biosynthesis and chloroplast development were differentially expressed in the OsDXR knock-out lines compared to the wild type.Moreover, we found that the RNA editing efficiencies of ndhA-1019 and rpl2-1 were significantly reduced in the OsDXR knock-out lines. Furthermore, OsDXR interacted with the RNA editing factor OsMORF1 in a yeast two-hybrid screen and bimolecular fluorescence complementation assay. Finally, disruption of the plastidial 2-C-methyl-derythritol-4-phosphate pathway resulted in defects in chloroplast development and the RNA editing of chloroplast genes.
基金supported by the National Natural Science Foundation of China(Grant Nos.30400276 and 30871480)the National Natural Science Foundation of Major International Cooperation Project(Grant No.31061140457)+1 种基金the Natural Science Foundation of Jiangsu Province,China(Grant No.BK2009005)the Scientific Research Foundation for the Talents of Jiangsu Province,China
文摘The accumulation dynamics of kernel components for spikelets at different positions within a rice panicle were investigated during grain filling to understand the physiological reasons for the variation of grain quality.Two rice cultivars,Yangdao 6 （indica） and Yangjing 9538 （japonica）,were field-grown,and the grain filling characters and contents of starch,soluble sugar,and protein of the spikelets at different positions were studied.There were significant differences in matter accumulation among spikelets at different positions during grain filling.The early-flowering spikelets presented dominance over the late-flowering spikelets in initial time and initial rate of accumulation.At the initial and mid filling stages,the contents and the rates of starch and amylose accumulation in spikelets decreased with the flowering sequence,but soluble sugar content （SSC） exhibited the opposite trend.The difference in SSC among the spikelets of Yangjing 9538 was greater than that of Yangdao 6,but amylose content in mature spikelets showed no obvious relationship to their flowering sequence.The crude protein content （CPC） of early-flowering spikelets decreased more rapidly than that of late-flowering ones at the initial filling stage,and CPC in the spikelets on the secondary branch was higher than that on the primary branch,but CPC in early-flowering ones was lower than that in late-flowering across the whole grain filling period.Grain water content （GWC） of early-flowering spikelets decreased more rapidly than that of late-flowering spikelets on the same branch at the initial and mid filling stages,especially for the top grain on each primary branch.The results suggested that poor grain filling of late-flowering spikelets may be attributed to their low biological activity rather than carbohydrate supply limitation.
