Embryo-endosperm interaction strongly affects the developmental process of seeds and hence the formation of crop yield and quality. However, signals that orchestrate developmental processes of the two compartments are largely unknown. This study aims to provide an integrative landscape of rice seed development by organizing the information about embryo-endosperm interaction. Using a mutant with notched-belly grains, we devised a novel comparison method that can quantitatively evaluate the effect of embryo on the developmental process of endosperm, by comparing the upper and bottom endosperms of the mutant. Global comparison of mRNAs datasets in embryo and endosperm samples collected from 5 DAF (day after fertilization) through maturity uncovered a dragging effect of embryo on the developmental transition of the endosperm, extending the middle stage and delaying the late stage. Biochemical analysis revealed that signaling pathways of T6P-SnRK1, and GA or IAA may be involved in mediating this developmental transition. Integrating the information about embryo-endosperm bidirectional dialogue enables a new rice seed developmental staging system to be proposed. The results obtained should be valuable for elucidating the biological processes and signatures of grain formation, hence providing a valuable resource for modifying the molecular and physiological processes responsible for cereal grain yield and quality.

With the intensification of global warming, rice production is facing new challenges. Field evidence indicates increased temperature during rice grain-filling lead to a further deterioration of grain quality. Clarifying the potential regulation mechanism of elevated temperature on rice development and quality formation will be contributed to develop suitable cultivation measures to better cope with climate warming in the future. In this study, open field warming and DIA mass spectrometry were conducted to explore the regulatory effects of high temperature on pathways related to grain development and material accumulation during the formation of rice quality. 840 differentially expressed proteins (fold change > 2, p-value < 0.05) were identified when exposed to high temperature. Among these, prolamin PPROL 14E, PSB28, granule-bound starch synthase 1 and 26.7 kDa heat shock protein were the most significantly regulated, and that ultimately affected the main substances accumulation of starch and protein in the kernel, and further degraded rice quality under high temperature. In addition, the results provided novel targets involved in regulating the metabolism of storage compounds under warming environment, and that will help us to better understand the regulation mechanism of global warming on the formation of rice quality.