Molecular analyses of the rice tubby-like protein gene family and their response to bacterial infection.

Tubby-like protein family has been identified in various multicellular organisms, indicating its fundamental functions in the organisms. However, the roles of plant tubby-like proteins are unknown. In this study, we have defined the tubby-like protein gene (OsTLP) family with 14 members in rice. Most of the OsTLPs harbor a tubby domain in their carboxyl terminus and an F-box domain in the amino terminus. The expression of all the OsTLPs was induced on infection of Xanthomonas oryzae pv. oryzae, which causes bacterial blight, one of the most devastating diseases of rice worldwide. The maximal expression levels were observed at 2-8 h after infection for all the genes. Eight of the 14 OsTLPs were also responsive to wounding. All the OsTLPs showed differential expression in different tissues at different developmental stages. However, four pairs of the 14 OsTLPs, with each pair having high sequence similarity and distributing on the similar position of different chromosomes, showed similar expression pattern in different tissues, indicating their direct relationship in evolution. These results suggest that the OsTLP family is involved in host-pathogen interaction and it may be also associated with other physiological and developmental activities.