Functional characterization of GPC-1 genes in hexaploid wheat
Functional characterization of GPC-1 genes in hexaploid wheat
复制标题
DOI：
10.1007/s00425-013-1977-y
复制
发表时间：
2014-02-01
期刊：
影响因子：
4.3
通讯作者：
Distelfeld, Assaf
中科院分区：
文献类型：
--
作者：
Avni, Raz;Zhao, Rongrong;Distelfeld, Assaf
小麦一次结实衰老是一个严格调控的过程，在此过程中，花前储存的氮（N）和微量营养元素从营养组织重新分配到发育中的籽粒中。近年来，通过对小麦籽粒蛋白质含量（GPC）基因的图位克隆，揭示了衰老与再动员之间的密切关系。GPC-B1编码NAC转录因子，与提早衰老和增加籽粒蛋白质、铁和锌含量相关，并且在大多数商业小麦品种中缺失或无功能。在目前的研究中，我们确定了“功能丧失”甲基磺酸乙酯突变体的两个GPC-B1同源基因; GPC-A1和GPC-D1，在六倍体小麦突变群体。单gpc-a1和gpc-d1突变体，双gpc-1突变体和控制线在四个地点的田间条件下生长，并进行了表征衰老，GPC，微量营养素和产量参数。我们的研究结果表明，在本研究中测试的所有环境中，gpc-a1和gpc-d1单突变体都显着延迟衰老，而gpc-1双突变体的效果甚至更强。发育中的谷粒中总氮的积累表现出类似的增加，直到开花后25天（DAA）的对照和gpc-1植物，但在41和60 DAA的对照植物有较高的谷粒氮含量比gpc-1突变体。成熟时，GPC在所有突变体显着低于对照植物，而粒重不受影响。这些结果表明，GPC-A1和GPC-D1基因具有冗余功能，在小麦一次结实衰老和养分再动员的调控中起主要作用。
In wheat, monocarpic senescence is a tightly regulated process during which nitrogen (N) and micronutrients stored pre-anthesis are remobilized from vegetative tissues to the developing grains. Recently, a close connection between senescence and remobilization was shown through the map-based cloning of the GPC (grain protein content) gene in wheat. GPC-B1 encodes a NAC transcription factor associated with earlier senescence and increased grain protein, iron and zinc content, and is deleted or non-functional in most commercial wheat varieties. In the current research, we identified 'loss of function' ethyl methanesulfonate mutants for the two GPC-B1 homoeologous genes; GPC-A1 and GPC-D1, in a hexaploid wheat mutant population. The single gpc-a1 and gpc-d1 mutants, the double gpc-1 mutant and control lines were grown under field conditions at four locations and were characterized for senescence, GPC, micronutrients and yield parameters. Our results show a significant delay in senescence in both the gpc-a1 and gpc-d1 single mutants and an even stronger effect in the gpc-1 double mutant in all the environments tested in this study. The accumulation of total N in the developing grains showed a similar increase in the control and gpc-1 plants until 25 days after anthesis (DAA) but at 41 and 60 DAA the control plants had higher grain N content than the gpc-1 mutants. At maturity, GPC in all mutants was significantly lower than in control plants while grain weight was unaffected. These results demonstrate that the GPC-A1 and GPC-D1 genes have a redundant function and play a major role in the regulation of monocarpic senescence and nutrient remobilization in wheat.