Genome-wide characterization and expression profiling of MADS-box family genes during organ development and drought stress in Camelina sativa L.

Camelina sativa stands out among oilseed crops due to its remarkable resilience to challenging environmental conditions and its significant potential for biodiesel production. The MADS-box transcription factors play a pivotal role in numerous biological processes within plants, encompassing growth, development, and responses to environmental stressors. In this research, by employing the BLAST, we have successfully identified 325 MADS-box genes within Camelina sativa genome. These genes were systematically categorized into two principal groups: type I (comprising Mα, Mβ, and Mγ) and type II (including MI-KC and MIKC) predicated upon their phylogenetic relationships, structural protein motifs, and exon-intron configurations. Our findings reveal that type II MADS-box genes have, in general, experienced a more profound expansion relative to type I genes. Specifically, the TM3 subgroup within type II MADS-box genes exhibited the highest degree of gene expansion, comprising 21 TM3 genes. The amino acid sequences encoded by these genes exhibited a length variation ranging from 150 to 820 aa. The predicted molecular weights (MW) of the CsMADS-box proteins displayed a range from 17.01 to 94.06 kDa, while the isoelectric points (pI) were observed to span from 4.13 to 10.09. Evolutionary analysis predicated on the Ka/Ks ratios indicates that the evolutionary pathway of MADS-box genes in Camelina sativa has been predominantly driven by the mechanisms of purifying selection. Moreover, an investigation of cis-acting elements has elucidated the participation of MADS-box genes in the adaptive responses to abiotic stressors. The expression profiles of six Type I and three MIKC genes across diverse organs and under varying drought treatment conditions demonstrated that these genes are expressed in both reproductive and vegetative structures, displaying uniform expression patterns throughout several developmental phases of flowering. The expression levels of CsMADS035, CsMADS115, CsMADS131, and CsMADS181 were notably modified in reaction to drought stress conditions. The detailed annotation and comprehensive transcriptome profiling provided in this research yield essential insights into the functional roles that MADS-box genes perform in stress resistance, as well as their contributions to growth and developmental processes. This acquired understanding establishes a foundational framework for the functional characterization and potential genetic engineering initiatives pertaining to Camelina sativa, thereby augmenting the prospective application of these candidate genes.