RESUMO
The use of alkaline salt lands for crop production is hindered by a scarcity of knowledge and breeding efforts for plant alkaline tolerance. Through genome association analysis of sorghum, a naturally high-alkaline-tolerant crop, we detected a major locus, Alkaline Tolerance 1 (AT1), specifically related to alkaline-salinity sensitivity. An at1 allele with a carboxyl-terminal truncation increased sensitivity, whereas knockout of AT1 increased tolerance to alkalinity in sorghum, millet, rice, and maize. AT1 encodes an atypical G protein γ subunit that affects the phosphorylation of aquaporins to modulate the distribution of hydrogen peroxide (H2O2). These processes appear to protect plants against oxidative stress by alkali. Designing knockouts of AT1 homologs or selecting its natural nonfunctional alleles could improve crop productivity in sodic lands.
Assuntos
Álcalis , Produtos Agrícolas , Subunidades gama da Proteína de Ligação ao GTP , Proteínas de Plantas , Tolerância ao Sal , Sorghum , Produtos Agrícolas/genética , Produtos Agrícolas/fisiologia , Peróxido de Hidrogênio/metabolismo , Oryza/genética , Oryza/fisiologia , Estresse Oxidativo/genética , Melhoramento Vegetal , Salinidade , Álcalis/análise , Álcalis/toxicidade , Bicarbonato de Sódio/análise , Bicarbonato de Sódio/toxicidade , Carbonatos/análise , Carbonatos/toxicidade , Tolerância ao Sal/genética , Sorghum/genética , Sorghum/fisiologia , Subunidades gama da Proteína de Ligação ao GTP/genética , Subunidades gama da Proteína de Ligação ao GTP/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/fisiologia , Aquaporinas/metabolismo , Produção Agrícola , Loci Gênicos , Solo/químicaRESUMO
Alfalfa (Medicago sativa L.) is the most widely cultivated leguminous herb in the world. Its agricultural development has been restricted by various adverse environmental conditions, including water deficiency, high salinity, and low temperature. WRKY transcription factors (TFs) serve important roles in the regulation of plant development and stress responses. Research on the WRKY gene family has been reported for several species, but minimal information is available for alfalfa. In the present study, a total of 107 WRKY genes were identified in alfalfa and divided into 3 main groups. The classification, evolution, conserved motifs, and tissue expression were comprehensively analyzed. Meanwhile, 27 MsWRKY candidate genes that may be involved in abiotic stress were isolated through an analysis of gene expression profiles under different stresses, including cold, abscisic acid, drought, and salt treatments. Additionally, investigation of the cis-elements and potential biological functions of these genes further revealed that MsWRKY TFs may serve important roles in multiple stress resistance in alfalfa. This study provides an important foundation for future cloning and functional studies of WRKY genes in alfalfa.
