Mutation of OsKIF14.3, a Kinesin-14 Subfamily Protein, Altered Starch Metabolism and Caused Yellowish Leaf in Rice

The Kinesin superfamily members are ATP-dependent microtubule-based motor proteins that are conserved among all eukaryotic organisms and play vital roles in diverse cellular processes, such as vesicle trafficking, mitosis and meiosis, and cytoskeletal dynamics. Here, OsKIF14.3, a kinesin-14 subfamily protein, was map-based cloned and functionally analyzed. The <i>OsKIF14.3</i> gene exhibited a constitutive expression pattern. OsKIF14.3 protein localized on the microtubule and formed homodimer via the conserved Coiled Coil 1 (CC1) domain. Mutation of <i>OsKIF14.3</i> altered OsSWEET11's subcellular location from the plasma membrane into both the plasma membrane and the cytoplasm, leading to abnormal starch metabolism, excess starch accumulation in the chloroplast, broken stroma lamella and yellowish leaves in <i>oskif14.3</i> mutant. These results enriched our understanding of the kinesin superfamily and leaf color regulation mechanism.