Wild type rice OsCERK1DY-mediated arbuscular mycorrhiza symbiosis boosts yield and nutrient use efficiency in rice breeding

Abstract

Abstract Meeting the food demands of an ever-increasing population on the basis of resource and environmental sustainability poses major challenges to agriculture worldwide. Arbuscular mycorrhizal symbiosis (AMS) can increase the surface area of a plant’s root system, promote the absorption of phosphorus and nitrogen nutrients as well as water. Thus, it has long been theorized that rice varieties with more efficient AM symbiosis could have enhanced yield and reduced input costs, it is a new direction for the development of Green Super Rice (GSR). Our previous study identified that a variant OsCERK1DY from Dongxiang wild type rice, significanly increased the efficiency AMS in rice cultivar "ZZ35", making it an ideal gene to improve yield and nutrient use effeciency in rice breeding. In this study, we compared and examined the biomass, crop growth characteristics, yield attributes, and nutrient absorption at different soil nitrogen levels in rice cultivar "ZZ35" and its chromosome single-segment substitution line "GJDN1". The AM colonization level in GJDN1 roots was higher than that of ZZ35 in the field. Compared with ZZ35, the effective panicle number and seed-setting rate in GJDN1 were significantly higher, and the yield of GJDN1 at 75% nitrogen was 14.27% higher than the maximum yield achieved by ZZ35. When grown at the same nitrogen level, GJDN1 values were significantly higher than those of ZZ35 for the chlorophyll content, dry matter accumulation at the mature stage, population growth rate from full heading stage to mature stage, accumulation of major nutrient elements, nitrogen absorption rate from sowing stage to full heading stage, N agronomic efficiency (NAE), N recovery efficiency (NRE), and N partial factor productivity (NPFP). These results support a model in which the high level of AM symbiosis mediated by OsCERK1DY promotes the accumulation of nitrogen, phosphorus, and potassium, and improves the utilization rate of fertilizer, dry matter accumulation, and yield of rice. Thus, the OsCERK1DY gene is a strong candidate for improving yield, reducing fertilizer use, and transitioning towards greener, lower carbon agriculture.