1 School of Pharmaceutical Sciences, Academy of Chinese Medical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, China; 2 Songyang Institute, Zhejiang Chinese Medical University, Lishui 323400, China
Abstract：SQUAMOSA promoter binding protein-like (SPL) is a transcription factor that plays a crucial role in plant growth and development, as well as stress response. In this study, the DoSPL gene family was identified based on the whole genome of Dendrobium officinale through the bioinformatics approach. Their chromosome position, composition of promoter elements, gene structure, phylogeny, and subcellular localization were analyzed. Meanwhile, their expression patterns in different tissues and under stresses were detected using real-time quantitative reverse transcription PCR (qRT-PCR). Results showed that D. officinale harbored a total of 16 SPL family members, all contained SBP zinc finger structure, and divided into 7 subfamilies. Majority of them were hydrophilic proteins, located in the nucleus, anchored on 10 chromosomes, and possessed 3 tandem repeat gene pairs. Many regulatory elements associated with growth and development, and stress response were presented in the upstream promoter regions of DoSPLs. Multi-species phylogenetic analysis revealed that D. officinale was phylogenetically close to rice (Oryza sativa) SPL proteins. Gene expression analysis showed that DoSPLs were significantly and differentially expressed in different tissues of D. officinale, and exhibited high expression in flowers. Most DoSPLs genes were evidently upregulated or downregulated under the induction of low temperature, methyl jasmonate, or salt stress. Specially, DoSPL12 was significantly upregulated under the above stresses, and might play a crucial role in stress responses. This study provides fundamental data for further exploration the function of the DoSPL gene family.
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