RESUMO
The DEAD-box family is the largest family of RNA helicases (RHs), playing crucial roles in RNA metabolism and plant stress resistance. In this study, we report that an RNA helicase, RH12, positively regulates plant salt tolerance, as rh12 knockout mutants exhibit heightened sensitivity to salt stress. Further analysis indicates that RH12 is involved in the abscisic acid (ABA) response, as rh12 knockout mutants show increased sensitivity to ABA. Examination of reactive oxygen species (ROS) revealed that RH12 helps inhibit ROS accumulation under salt stress during seed germination. Additionally, RH12 accelerates the degradation of specific germination-related transcripts. In conclusion, our results demonstrate that RH12 plays multiple roles in the salt stress response in Arabidopsis.
Assuntos
Ácido Abscísico , Proteínas de Arabidopsis , Arabidopsis , RNA Helicases DEAD-box , Germinação , Tolerância ao Sal , Sementes , Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Germinação/genética , Tolerância ao Sal/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , RNA Helicases DEAD-box/metabolismo , RNA Helicases DEAD-box/genética , Sementes/genética , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Ácido Abscísico/metabolismo , Regulação da Expressão Gênica de Plantas , Espécies Reativas de Oxigênio/metabolismoRESUMO
Plant lateral roots (LRs) play vital roles in anchorage and uptake of water and nutrients. Here, we reveal that degradation of lariat intronic RNAs (lariRNAs) modulated by SICKLE (SIC) is required for LR development in Arabidopsis (Arabidopsis thaliana). Loss of SIC results in hyper-accumulation of lariRNAs and restricts the outgrowth of LR primordia, thereby reducing the number of emerged LRs. Decreasing accumulation of lariRNAs by over-expressing RNA debranching enzyme 1 (DBR1), a rate-limiting enzyme of lariRNA decay, restored LR defects in SIC-deficient plants. Mechanistically, SIC interacts with DBR1 and facilitates its nuclear accumulation, which is achieved through two functionally redundant regions (SIC1-244 and SIC252-319) for nuclear localization. Of the remaining amino acids in this region, six (SIC245-251) comprise a DBR1-interacting region while two (SICM246 and SICW251) are essential for DBR1-SIC interaction. Reducing lariRNAs restored microRNA (miRNA) levels and LR development in lariRNA hyper-accumulating plants, suggesting that these well-known regulators of LR development mainly function downstream of lariRNAs. Taken together, we propose that SIC acts as an enhancer of DBR1 nuclear accumulation by driving nuclear localization through direct interaction, thereby promoting lariRNA decay to fine-tune miRNA biogenesis and modulating LR development.