Speakers

Biography

Prof. Jin-Ying Gou mainly studies the molecular genetics of wheat stripe rust resistance and yield. To explore their molecular mechanism, Prof. Gou cloned genes promoting wheat stripe rust endurance and CO2 assimilation rate. Prof. Gou They were focused on metabolic regulation to explore strategies toward durable and broad-spectrum resistance potential. To comprehensively investigate the application potential of candidate genes, Prof. Gou examined their effect on photo-assimilation rates and yield traits. Prof. Gou evaluated their disease resistance, yield potential, and functional quality to explore the strategy of coupling disease resistance, high yield, and nutritional function regulation. The work could provide a theoretical basis and valuable germplasm resources for disease-resistance breeding.

Abstract

The elongation of photosynthesis, or functional stay-green, represents a feasible strategy to propel metabolite flux toward cereal kernels. However, achieving the above goal remains a stunting challenge in food crops. Here, we report the cloning of wheat CO₂ assimilation and kernel enhanced 2 (cake2), the mechanism underlying the photosynthesis advantages, and natural alleles amiable for breeding elite varieties. We isolated cake2 from a tetraploid wheat EMS mutant library. We detected a premature stop mutation in the A-genome copy of the ASPARTIC PROTEASE 1 (APP-A1) gene (henceforth app-A1) that co-segregates with the cake2 phenotype. A splicing mutant in the B-genome homolog (app-B1) and the double mutant (app1) enhanced photosynthesis and grain size/weight. On the contrary, overexpression of APP-A1 accelerated leaf senescence and complemented the cake2 phenotype. APP-A1 A genome is an active chloroplast protease, bound and degraded PsbO, the protective extrinsic member of photosystem II (PS II). A dysfunction mutant of PsbO (psbo-2A) partially complemented the app1 double mutant, indicating PsbO’s contribution to the enhanced function of PS II and grain development in app1. Furthermore, a natural polymorphism of the APPA1 gene in common wheat reduced APP-A1’s activity and promoted photosynthesis and grain size/weight. This work demonstrates that modification in APP1 can positively affect photosynthesis and grain size and inform future steps to understand and engineer the functional stay-green phenotype. The genetic resources could propel photosynthesis and high-yield potentials in tetraploid and hexaploid wheat elite varieties.