Decena Maria Angeles, Gálvez-Rojas Sergio, Agostini Federico, Sancho Ruben, Contreras-Moreira Bruno, Des Marais David L, Hernandez Pilar, Catalán Pilar
Escuela Politécnica Superior de Huesca, Universidad de Zaragoza, Ctra. Cuarte km 1, 22071 Huesca, Spain.
ETSI Informática, Universidad de Málaga, Blvr Louis Pasteur 35, 29071 Málaga, Spain.
Plants (Basel). 2021 Dec 3;10(12):2664. doi: 10.3390/plants10122664.
Dehydration proteins (dehydrins, DHNs) confer tolerance to water-stress deficit in plants. We performed a comparative genomics and evolutionary study of DHN genes in four model grass species. Due to limited knowledge on dehydrin expression under water deprivation stress in we also performed a drought-induced gene expression analysis in 32 ecotypes of the genus' flagship species showing different hydric requirements. Genomic sequence analysis detected 10 types of dehydrin genes () across the species. Domain and conserved motif contents of peptides encoded by genes revealed eight protein architectures. genes were spread across several chromosomes. Selection analysis indicated that all the genes were constrained by purifying selection. Three upstream -regulatory motifs (BES1, MYB124, ZAT) were detected in several genes. Gene expression analysis demonstrated that only four 1-2, 3, and 7 genes, orthologs of wheat, barley, rice, sorghum, and maize genes, were expressed in mature leaves of and that all of them were more highly expressed in plants under drought conditions. dehydrin expression was significantly correlated with drought-response phenotypic traits (plant biomass, leaf carbon and proline contents and water use efficiency increases, and leaf water and nitrogen content decreases) being more pronounced in drought-tolerant ecotypes. Our results indicate that dehydrin type and regulation could be a key factor determining the acquisition of water-stress tolerance in grasses.
脱水蛋白（脱水素，DHNs）赋予植物对水分胁迫亏缺的耐受性。我们对四种模式禾本科植物中的脱水素基因进行了比较基因组学和进化研究。由于对水分剥夺胁迫下脱水素表达的了解有限，我们还对该属旗舰物种的32个生态型进行了干旱诱导基因表达分析，这些生态型表现出不同的水分需求。基因组序列分析在这些物种中检测到10种脱水素基因（ ）。脱水素基因编码的肽段的结构域和保守基序内容揭示了八种蛋白质结构。脱水素基因分布在几条染色体上。选择分析表明，所有脱水素基因都受到纯化选择的限制。在几个脱水素基因中检测到三种上游调控基序（BES1、MYB124、ZAT）。基因表达分析表明，只有四个脱水素基因（1、2、3和7），即小麦、大麦、水稻、高粱和玉米基因的直系同源基因，在该物种的成熟叶片中表达，并且它们在干旱条件下的植物中表达量都更高。脱水素表达与干旱响应表型性状（植物生物量、叶片碳和脯氨酸含量增加以及水分利用效率提高，叶片水分和氮含量降低）显著相关，在耐旱生态型中更为明显。我们的结果表明，脱水素类型和调控可能是决定禾本科植物获得水分胁迫耐受性的关键因素。
