Stress‐induced F‐Box protein‐coding geneOsFBX257modulates drought stress adaptations and ABA responses in rice

Abstract

F‐box (FB) proteins that form part of SKP1‐CUL1‐F‐box (SCF) type of E3 ubiquitin ligases are important components of plant growth and development. Here we characterized OsFBX257, a rice FB protein‐coding gene that is differentially expressed under drought conditions and other abiotic stresses. Population genomics analysis suggest that OsFBX257 shows high allelic diversity in aus accessions and has been under positive selection in some japonica, aromatic and indica cultivars. Interestingly, allelic variation at OsFBX257 in aus cultivar Nagina22 is associated with an alternatively spliced transcript. Conserved among land plants, OsFBX257 is a component of the SCF complex, can form homomers and interact molecularly with the 14‐3‐3 rice proteins GF14b and GF14c. OsFBX257 is co‐expressed in a network involving protein kinases and phosphatases. We show that OsFBX257 can bind the kinases OsCDPK1 and OsSAPK2, and that its phosphorylation can be reversed by phosphatase OsPP2C08. OsFBX257 expression level modulates root architecture and drought stress tolerance in rice. OsFBX257 knockdown (OsFBX257KD) lines show reduced total root length and depth, crown root number, panicle size and survival under stress. In contrast, its overexpression (OsFBX257OE) increases root depth, leaf and grain length, number of panicles, and grain yield in rice. OsFBX257 is a promising breeding target for alleviating drought stress‐induced damage in rice.

Prospects for rice in 2050

“…Sharma et al (2022) deepened understanding of drought resistance in rice and further promoted efforts in developing drought-resilient rice varieties. They report that OsFBX257, a stress-induced F-Box protein, is indispensable for drought tolerance and maintenance of grain yield under drought conditions via positively modulating root depth and abscisic acid (ABA) responses in rice (Sharma et al, 2022). Sharma et al (2022) propose that OsFBX257 is a hub gene of a molecular network involving at least OsCDPK1-GF14c and OsSAPK2-OsPP2C08 two signalling pathways (Sharma et al, 2022), which could be a potential target for breeding drought-resilient rice.…”

“…Effects of drought on rice growth, development, production, and quality, as well as physiological and molecular responses have been reviewed previously (Panda et al, 2021; Y. Yang, Yu, et al, 2022). Sharma et al (2022) deepened understanding of drought resistance in rice and further promoted efforts in developing drought‐resilient rice varieties. They report that OsFBX257, a stress‐induced F‐Box protein, is indispensable for drought tolerance and maintenance of grain yield under drought conditions via positively modulating root depth and abscisic acid (ABA) responses in rice (Sharma et al, 2022).…”

Two splice forms ofOsbZIP1, a homolog ofAtHY5, function to regulate skoto- and photo-morphogenesis in rice

“…For BiFC and subcellular localization, particle bombardment was performed using the Biolistic PDS-1000/He particle delivery system (Bio-Rad, USA) according to the protocol described earlier (Sharma et al, 2022). After particle bombardment of the onion peel cells, they were kept at 28±1°C in dark for 16 h and observed under confocal microscope (Leica microsystems, TCS, SP5).…”

Identification and Fine Mapping of Osdsm3, a Drought-Sensitive Gene in Rice (Oryza sativa L.)

“…The OsFBX257 gene, which is responsible for encoding an F-Box protein, plays a crucial role in enhancing ABA signaling. The gene's function and expression level have a significant impact on both root and shoot development, and it can also influence rice drought stress tolerance in controlled environments [23]. OsbZIP23 and OsbZIP72 are considered key regulators in ABA-dependent drought and salt stress responses.…”