Functional characterization of GPC-1 genes in hexaploid wheat

• Autores: Avni, Raz; Zhao, Rongrong; Pearce, Stephen; Jun, Yan; Uauy, Cristobal; Tabbita, Facundo; Fahima, Tzion; Slade, Ann; Dubcovsky, Jorge; Distelfeld, Assaf
• Año de publicación: 2014
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: GRAIN PROTEIN CONTENT; SENESCENCE; WHEAT; MUTANTS
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

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.
Fil: Avni, Raz. Tel Aviv University; Israel
Fil: Zhao, Rongrong. China Agricultural University; República de China. University of California at Davis; Estados Unidos
Fil: Pearce, Stephen. University of California at Davis; Estados Unidos
Fil: Jun, Yan. University of Haifa; Israel
Fil: Uauy, Cristobal. University of California at Davis; Estados Unidos
Fil: Tabbita, Facundo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. University of California at Davis; Estados Unidos
Fil: Fahima, Tzion. University of Haifa; Israel
Fil: Slade, Ann. Arcadia Biosciences Inc.; Estados Unidos
Fil: Dubcovsky, Jorge. University of California at Davis; Estados Unidos
Fil: Distelfeld, Assaf. Tel Aviv University; Israel