The Arabidopsis LARP1s are Involved in Regulation of Seed Germination

Members of La-related protein (LARP) 1 family spread widely in various species, and they are involved in regulating many important biological processes in mammal, yeast, and fruit fly. However, functional research of LARP1s in plants is limited so far. In Arabidopsis, there are three members in LARP1 family, LARP1a, 1b, and 1c. Here, we found that the mutation of LARP1 genes delayed seed germination, implying that LARP1 proteins might be positive factors of seed germination in Arabidopsis. Moreover, the larp1 mutants showed more sensitive to abscisic acid (ABA) and paclobutrazol (PAC), as larp1 mutants displayed low rate of germination in medium contained ABA or PAC. Temporal and spatial expression analyses revealed that LARP1s were more abundant in seeds, especially in imbibed seeds. Subcellular localization analysis revealed that all LARP1 proteins could localize to the P-bodies, suggesting that LARP1s might play a role in RNA processes. Taken together, our results unravel new conserved functions of LARP1s in the regulation of Arabidopsis seed germination.