RT Journal Article
SR Electronic
T1 OsIQD14 regulates rice grain shape through modulating the microtubule cytoskeleton
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 275552
DO 10.1101/275552
A1 Baojun Yang
A1 Jos R. Wendrich
A1 Bert De Rybel
A1 Dolf Weijers
A1 HongWei Xue
YR 2018
UL http://biorxiv.org/content/early/2018/03/02/275552.abstract
AB Cortical microtubule (MT) arrays play a critical role in plant cell shape determination by defining the direction of cell expansion1-3. The control of plant organ shape and architecture is a major target of cereal crop improvement. Given the pleiotropic effects of MT modification, however, it is challenging to exploiting MT array organization for crop improvement. Moreover, as plants continuously adapt cell growth and expansion to ever-changing environmental conditions, multiple environmental (e.g. light4) and developmental (e.g. hormones5,6) inputs need to be translated into changes of the MT cytoskeleton. Here, we identify and functionally characterize an auxin-inducible and MT-localized protein OsIQ67-DOMAIN14 (OsIQD14), which is highly expressed in rice seed hull cells. While deficiency of OsIQD14 results in short and wide seeds and increases overall yield, overexpression leads to narrow and long seeds, caused by changes in the direction of MT arrangement. We further show that OsIQD14-mediated MT reordering is regulated through interacting with SPIRAL2, a MT-binding protein involved in KATANIN1-mediated MT rearrangement7,8, and with calmodulin proteins. As such, OsIQD14 acts as an integrator of auxin and calcium inputs into MT rearrangements, and allows effective local cell shape manipulation to improve a key rice yield trait.