Genome-Wide Identification and Characterization of Short-Chain Dehydrogenase/Reductase (SDR) Gene Family in Medicago truncatula

Abstract

Short-chain dehydrogenase/reductase (SDR) belongs to the NAD(P)(H)-dependent oxidoreductase superfamily. Limited investigations reveal that SDRs participate in diverse metabolisms. A genome-wide identification of the SDR gene family in <i>M. truncatula</i> was conducted. A total of 213 <i>MtSDR</i> genes were identified, and they were distributed on all chromosomes unevenly. MtSDR proteins were categorized into seven subgroups based on phylogenetic analysis and three types including 'classic', 'extended', and 'atypical', depending on the cofactor-binding site and active site. Analysis of the data from <i>M. truncatula</i> Gene Expression Atlas (MtGEA) showed that above half of <i>MtSDRs</i> were expressed in at least one organ, and lots of <i>MtSDRs</i> had a preference in a tissue-specific expression. The <i>cis</i>-acting element responsive to plant hormones (salicylic acid, ABA, auxin, MeJA, and gibberellin) and stresses were found in the promoter of some <i>MtSDRs</i>. Many genes of <i>MtSDR</i>7<i>C,</i><i>MtSDR</i>65<i>C</i><i>, MtSDR</i>110<i>C</i><i>, MtSDR</i>114<i>C</i>, and <i>MtSDR108E</i> families were responsive to drought, salt, and cold. The study provides useful information for further investigation on biological functions of MtSDRs, especially in abiotic stress adaptation, in the future.