Auxin Transporter OsPIN1b, a Novel Regulator of Leaf Inclination in Rice (Oryza sativa L.)

Abstract

Leaf inclination is one of the most important components of the ideal architecture, which effects yield gain. Leaf inclination was shown that is mainly regulated by brassinosteroid (BR) and auxin signaling. Here, we reveal a novel regulator of leaf inclination, auxin transporter OsPIN1b. Two CRISPR-Cas9 homozygous mutants, ospin1b-1 and ospin1b-2, with smaller leaf inclination compared to the wild-type, Nipponbare (WT/NIP), while overexpression lines, OE-OsPIN1b-1 and OE-OsPIN1b-2 have opposite phenotype. Further cell biological observation showed that in the adaxial region, OE-OsPIN1b-1 has significant bulge compared to WT/NIP and ospin1b-1, indicating that the increase in the adaxial cell division results in the enlarging of the leaf inclination in OE-OsPIN1b-1. The OsPIN1b was localized on the plasma membrane, and the free IAA contents in the lamina joint of ospin1b mutants were significantly increased while they were decreased in OE-OsPIN1b lines, suggesting that OsPIN1b might action an auxin transporter such as AtPIN1 to alter IAA content and leaf inclination. Furthermore, the OsPIN1b expression was induced by exogenous epibrassinolide (24-eBL) and IAA, and ospin1b mutants are insensitive to BR or IAA treatment, indicating that the effecting leaf inclination is regulated by OsPIN1b. This study contributes a new gene resource for molecular design breeding of rice architecture.

Expression of a mammalian RNA demethylase increases flower number and floral stem branching in Arabidopsis thaliana

“…Specifically, we found SAUR10, SAUR28, SAUR63, and SAUR68 to be highly upregulated. SAUR10 has been shown to increase growth when overexpressed in Arabidopsis 30 , and was recently shown to be essential for normal growth and yield in rice 31 . SAUR28, along with three other nearby SAUR genes, was identified as the largest effect QTL for leaf architecture changes at bolting stage in response to different temperatures 32 .…”

Deficiency of Auxin Efflux Carrier OsPIN1b Impairs Chilling and Drought Tolerance in Rice

“…Rice japonica variety Nipponbare and ospin1b mutants [58] were employed for the experiments. Rice plants were cultured using hydroponic systems according to our previous report [24]. In brief, after sterilization, rice seeds were incubated in Petri dishes with wetted filter papers at 28-30 • C for several days in the dark.…”

“…By contrast, the mutation of OsPIN1b by CRISPR/Cas9 technology causes no obvious phenotype in rice, only ospin1a ospin1b double mutants show pleiotropic phenotypes [23]. Recently, Zhang et al reported that OsPIN1b participates in regulating leaf inclination in rice [24]. Additionally, nutrient supply influences OsPIN1b expression; for example, sufficient nitrate conditions significantly induce OsPIN1b expression [25], whereas low-nitrogen and -phosphate conditions significantly down-regulate OsPIN1b expression.…”

Improved Short-Term Wind Power Forecasts: Low-Latency Feedback Error Correction Using Ramp Prediction and Data From Nearby Farms

“…The first is to detect ramps from a time series of wind power or wind speed forecasts according to a given ramp-event definition [37]. The second strategy is to use regression to predict ramp-events from historical data [38], [39]. According to [38], the ramp capture rate was less than 50% for most cases.…”