Abstract
SummaryERECTA PANICLE 3 (EP3) and ORYZA SATIVA F‐BOX KELCH 1 (OsFBK1) proteins share 57% and 54% sequence identity with the Arabidopsis F‐box protein HAWAIIAN SKIRT (HWS). Previously we showed that EP3 is a functional orthologue of HWS. Here we demonstrate that OsFBK1 is another functional orthologue of HWS and show the complexity of interaction between EP3 and OsFBK1 genes at different developmental stages of the plant. qRT‐PCR expression analyses and studies of EP3‐GFP and OsFBK1‐RFP promoter reporter lines demonstrate that although EP3 and OsFBK1 expression can be detected in the same tissues some cells exclusively express EP3 or OsFBK1 whilst others co‐express both genes. Loss, reduction or gain‐of‐function lines for EP3 and OsFBK1, show that EP3 and OsFBK1 affect plant architecture, organ size, floral organ number and size, floral morphology, pollen viability, grain size and weight. We have identified the putative orthologue genes of the rice microRNA pathway for ORYZA SATIVA DAWDLE (OsDDL) and ORYZA SATIVA SERRATE (OsSE), and demonstrated that EP3 and OsFBK1 affect their transcript levels as well as those of CROWN ROOT DEFECT 1/ORYZA SATIVA Exportin‐5 HASTY (CRD1/OsHST), ORYZA SATIVA DICER‐LIKE 1 (OsDCL) and ORYZA SATIVA WEAVY LEAF1 (OsWAF1). We show that EP3 affects OsPri‐MIR164, OsNAM1 and OsNAC1 transcript levels. OsNAC1 transcripts are modified by OsFBK1, suggesting two independent regulatory pathways, one via EP3 and OsMIR164 and the other via OsFBK1. Our data propose that EP3 and OsFBK1 conjointly play similar roles in rice to how HWS does in Arabidopsis.
Highlights
Ubiquitin protein degradation is a regulatory mechanism that affects many cellular processes including cell cycle, embryogenesis, development, floral formation, hormonal signalling, responses to stress and immunity in plants (Reed, 2003; Zhang et al, 2019)
We have demonstrated that ERECTA PANICLE 3 (EP3) is a functional orthologue of HAWAIIAN SKIRT (HWS) (Yu et al, 2015)
We show that transcripts of the rice CROWN ROOT DEFECT 1 (CRD1)/OsHST (Zhu, et al, 2019), ORYZA SATIVA DICER-LIKE 1 (OsDCL) and ORYZA SATIVA WEAVY LEAF1 (OsWAF1) reported microRNA biogenesis pathway genes are altered by EP3 and ORYZA SATIVA F-BOX KELCH 1 (OsFBK1)
Summary
Ubiquitin protein degradation is a regulatory mechanism that affects many cellular processes including cell cycle, embryogenesis, development, floral formation, hormonal signalling, responses to stress and immunity in plants (Reed, 2003; Zhang et al, 2019). The E3 ligase enzyme confers the required specificity by binding to the target substrate and the activated ubiquitin E2 complex, which is polyubiquitinated and targeted for degradation by the 26S proteasome (Sharma et al, 2016). 687 F-box proteins have been identified and shown to have diverse expression patterns, suggesting a range of roles during plant growth and development in response to internal and external signals (Jain et al, 2007)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
