Identification, expression and protein interaction analysis of Aux/IAA and ARF gene family in Senna tora L / 药学学报

The early response of plant auxin gene family Aux/IAA (auxin/indole-3-acetic acid) and its interaction with auxin response factor (ARF) are important pattern to regulate plant growth and development. This work identified 28 StoIAA and 24 StoARF members based on the whole genome data of the medicinal plant Senna tora L., which were classified into 10 and 8 subfamilies, respectively. Phylogenetic tree and collinearity analysis showed that S. tora has close evolutionary relationship with the IAA and ARF homologous genes of Glycine max, Medicago truncatula, and the segment duplication events dominate the expansion of StoIAA and StoARF. Gene structure analysis showed that the vast majority of StoIAA and StoARF contain characteristic conserved domain. Transcriptome data showed that StoIAAs and StoARFs were expressed in leaves, roots and seeds, some members had tissue specific expression. The StoIAA and StoARF promoter region most contain functional elements related to stress response, growth and development, hormone induction and secondary metabolism. In addition, gene expression analysis showed that many StoIAAs and StoARFs can quickly respond to drought and salt stress and exhibited same expression patterns under both stress condition. The yeast two-hybrid experiment confirmed that StoARF8 and StoARF10 exhibit varying degrees of interaction with multiple StoIAA proteins, respectively. The above results provide a basis for further biological functional analysis of the Aux/IAA and ARF gene family of S. tora.

miRNA-mediated regulation of auxin signaling pathway during plant development and stress responses

Auxin is one of the most important plant growth hormones, playing a crucial role in development as well as instress responses. Auxin biosynthesis and signaling pathway comprises a series of events including auxinperception by the receptor, activation, and function of auxin response factors and control by auxin repressors.All these factors are regulated by several different microRNAs during leaf, flower and fruit development,anther development, nodulation, lateral and adventitious root development, potato tuber development as wellas during heat stress, submergence, boron toxicity, aluminium stress responses, etc., as depicted in the availableliterature. In this review a thorough study on miRNA-mediated regulation of auxin biosynthesis and signalinghas been done in various plant species. The data gathered can be utilized to point out the particular miRNAmediated regulation module which can be utilized to modulate the expression of the miRNA and therebymodulation of the auxin pathway. Information in this review would be beneficial to utilize the miRNAexpression to generate the protocol for engineering plants with altered auxin signaling pathway to obtain betteryield and improved stress tolerance.