Molecular plant 2016 2
OsHAL3, a Blue Light-Responsive Protein, Interacts with the Floral Regulator Hd1 to Activate Flowering in Rice.
In flowering plants, photoperiodic flowering is controlled by a complicated network. Light is one of the most important environmental stimuli that control the timing of the transition from vegetative growth to reproductive development. Several photoreceptors, including ='term' data-tid='2019' href='#term-2019'>erm-2018'>data-tid='2017' href='#term-2017'>ss='term' data-tid='2016' href='#term-2016'>PHYA, PHYB, CRY2, and FKF1 in Arabidopsis and their homologs (OsPHYA, OsPHYB, OsPHYC, and OsCRY2) in rice, have been identified to be related to flowering. Our previous study suggests that OsHAL3, a flavin mononucleotide-binding protein, may function as a blue-light sensor. Here, we report the identification href='#term-2024'>'term' data-tid='2023' href='#term-2023'>of OsHAL3 as a positive regulator of flowering in rice. OsHAL3 overexpression lines exhibited an early flowering phenotype, whereas downregulation of OsHAL3 expression by RNA interference delayed flowering under an inductive photoperiod (short-day conditions). The change in flowering time was not accompanied by altered Hd1 expression but rather by reduced accumulation of Hd3a and MADS14 transcripts. OsHAL3 and Hd1 colocalized in the nucleus and physically interacted in vivo under the dark, whereas their interaction was inhibited by white or blue light. Moreover, OsHAL3 directly bound to the promoter of Hd3a, especially before dawn. We conclude that OsHAL3, a novel light-responsive protein, plays an essential role in photoperiodic control of flowering time in rice, which is probably mediated by forming a complex with Hd1. Our findings open up new perspectives on the photoperiodic flowering pathway.
|ss='||Os03g0309200||Q10MG9 A0A0P0VWK1 A0A0P0VWK6|
|data||Os11g0547000||Q2R2W1 Q0IS84 A0A0P0Y317|
|='term||Os03g0309200||Q10MG9 A0A0P0VWK1 A0A0P0VWK6|
|'</a>term' data||Os02g0115900||Q6Z7B0 A0A0P0VDX8|
|'term'||Os03g0752800||Q10CQ1 B9FBV1 A0A0P0W361|