Integration of embryo-endosperm interaction into a holistic and dynamic picture of seed development using a rice mutant with notched-belly grains

Abstract

The interaction between the embryo and endosperm affects seed development, an essential process in yield formation in crops such as rice. Signals that communicate between embryo and endosperm are largely unknown. Here we use the notched-belly (NB) mutant with impaired communication between embryo and endosperm to evaluate 1) the impact of embryo on developmental staging of the endosperm; 2) signaling pathways emanating from the embryo that regulate endosperm development. Hierachical clustering of mRNA datasets from embryo and endosperm samples collected through development in NB and wild type showed a delaying effect of the embryo on the developmental transition of the endosperm by extending the middle stage. K-means clustering further identified coexpression modules of gene sets specific for embryo and endosperm development. Combined gene expression and biochemical analysis showed that T6P-SnRK1, gibberellin and auxin signalling from the embryo regulate endosperm developmental transition. The data enable us to propose a new seed developmental staging system for rice and the most detailed signature of rice grain formation to date, that will direct genetic strategies for rice yield improvement.

Efficiency of Sucrose to Starch Metabolism Is Related to the Initiation of Inferior Grain Filling in Large Panicle Rice

“…Interestingly, the sugar signaling about the T6P-SnRK1 signaling pathway is significantly different in IS of CJ03 and W1844 during the grain-filling initiation period (Figure 8). As shown by previous researchers (Zhang et al, 2015;Tao et al, 2021), these data identified a novel role that the regulation of sugar signaling may be responsible for the metabolism efficiency of sucrose to starch in the grain-filling initiation of IS in large panicle rice.…”