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The mammalian BREAST CANCER 2 (BRCA2) gene is a tumor suppressor that plays a crucial role in DNA repair and homologous recombination (HR). Here, we report the identification and characterization of OsBRCA2, the rice orthologue of human BRCA2. Osbrca2 mutant plants exhibit normal vegetative growth but experience complete male and female sterility as a consequence of severe meiotic defects. Pairing, synapsis and recombination are impaired in osbrca2 male meiocytes, leading to chromosome entanglements and fragmentation. In the absence of OsBRCA2, localization to the meiotic chromosome axes of the strand-invasion proteins OsRAD51 and OsDMC1 is severely reduced and in vitro OsBRCA2 directly interacts with OsRAD51 and OsDMC1. These results indicate that OsBRCA2 is essential for facilitating the loading of OsRAD51 and OsDMC1 onto resected ends of programmed double-strand breaks (DSB) during meiosis to promote single-end invasions of homologous chromosomes and accurate recombination. In addition, treatment of osbrca2-1 seedlings with mitomycin C (MMC) led to hypersensitivity. As MMC is a genotoxic agent that creates DNA lesions in the somatic cells that can only be repaired by HR, these results suggest that OsBRCA2 has a conserved role in DSB repair and HR in rice.

Plants employ dynamic molecular networks to control development in response to environmental changes, yet the underlying mechanisms are largely unknown. Here we report the identification of two rice leucine-rich repeat receptor-like kinases, Thermo-Sensitive Genic Male Sterile 10 (TMS10) and its close homolog TMS10-Like (TMS10L), which redundantly function in the maintenance of the tapetal cell layer and microspore/pollen viability under normal temperature conditions with TMS10 playing an essential role in higher temperatures (namely, 28 °C). tms10 displays male sterility under high temperatures but male fertility under low temperatures, and the tms10 tms10l double mutant shows complete male sterility under both high and low temperatures. Biochemical and genetic assays indicate that the kinase activity conferred by the intracellular domain of TMS10 is essential for tapetal degeneration and male fertility under high temperatures. Furthermore, indica or japonica rice varieties that contain mutations in TMS10, created by genetic crosses or genome editing, also exhibit thermo-sensitive genic male sterility. These findings demonstrate that TMS10 and TMS10L act as a key switch in postmeiotic tapetal development and pollen development by buffering environmental temperature changes, providing insights into the molecular mechanisms by which plants develop phenotypic plasticity via genotype-environment temperature interaction. TMS10 may be used as a genetic resource for the development of hybrid seed production systems in crops.

This research aimed to comparatively evaluate the influences of root restriction (RR) cultivation and traditional cultivation (RC) on grape berry skin metabolomics using a non-targeted metabolomics method. Two-hundred-and-ninety-one metabolites were annotated and the kinetics analyses showed that berry skin metabolome is stage- and cultivation-dependent. Our results showed that RR influences significantly the metabolomes of berry skin tissues, particularly on secondary metabolism, and that this effect is more obvious at pre-veraison stage, which was evidenced by the early and fast metabolic shift from primary to secondary metabolism. Altogether, this study provided an insight into metabolic adaptation of berry skin to RR stress and expanded general understanding of berry development.