Development And Application Of Transcription Factor Gene-derived SSR Markers And Functional Analysis Of LEA Gene Family In Medicago Truncatula

As a leguminous model plant, Medicago truncatula could provide important genetic information for other legumes and herbages. At present, microsatellite(SSR) makers have become one of the most advanced markers. Transcription factors play key roles as trans-acting elements in the stress response and in plant growth and development. By now, a large set of EST-SSR markers derived from the M. truncatula genomic has been developed. However, no studies have yet reported on the development and usage of transcription factor(TF) gene-derived SSR markers of M. truncatula. In this study, development of TF-SSR primers are total 142 pairs using online tool, seventy primer pairs were selectcted randomly to assess their cross-species transferability in M. sativa, Nicotiana tabacum, Oryza sativa, Vicia sativa and Arabidopsis thaliana. The results indicated that 213 SSR sites have been detected from 187 TF family member squences, and the frequency was 14.52%. The cross-species transferability of 70 pairs of TF primers in M. sativa, tobacco, rice, common vetch and Arabidopsis thaliana were 77.14%,25.71%,27.14%,38.57% and 47.14%, respectively. Thus it can be seen, The high transferability of M. truncatula TF-SSR markers in leguminous and non-leguminous species, which will render these markers useful in the construction of linkage maps and for comparative genomic study and QTL discovery in the future.LEA protein is named the late-embryogensis abundant protein which is mainly expressed in higher plant late embryonic development. And when plant suffered some kinds of stress such as drought, high salinity, low temperature, ultraviolet radiation and NaHCO3, LEA was expressed most heavily. So, it was very useful in plant tolerance researching. In model plant Arabidopsis thaliana and Oryza sativa, LEA has been researched and reported. However, in M. truncatula, nobody has started to research LEA protein. In resent years, several model plant species have been finished sequencing analysis such as M. truncatula. In this study, with the application of bioinformatics methods, the LEA family genes of M. truncatula were identified through the whole genome, and the system evolution, gene structure, evolutionary pressure, chromosomal location and gene expression patterns were further analyzed. A total of 23 LEA genes systematically identified from M. truncatula and classified into 8 subfamilies. The expression profiles of M. truncatula LEA genes showed a characteristic of temporal and tissue specific, and regulated by drought stress. This study provides a theoretical foundation for verifying the function of LEA genes in M. truncatula.