Date: Sunday, January 15, 2012
Time: 9:40 AM
Time: 9:40 AM
Room: Pacific Salon 1
Phaseolus vulgaris (common bean) is one of the most important grain legumes for direct human consumption. It comprises 50% of the grain legumes consumed worldwide and is important as a primary source of dietary protein in developing countries. We have performed next generation sequencing (RNA-seq), Illumina-Sollexa platform, of different plant tissues from Phaseolus vulgaris cv. Negro Jamapa. RNA-seq of 24 RNA libraries from common bean seeds, pods, leaves roots and nodules at different stages of development, generated ca. 25 million 36-bp reads per sample. From these, 80, 462 transcripts were assembled and ca. 50,000 were annotated. Our libraries included: nitrogen-fixing nodules, non-fixing nodules –elicited by an inefficient rhizobia- and roots associated with the nodules. A total of seven RNA samples were collected at two distinct stages of nodule development: 5 and 21 days post inoculation. A sample of non-inoculated roots was used as a control. The latter allows a comprehensive transcriptome study of the relevant process of symbiotic nitrogen fixation (SNF) in the common bean - Rhizobium etli association. Comparative analyses of the expression profile has allowed the identification of genes specific for nodulation, nitrogen fixation, and changes induced in root tissues due to SNF. Our common bean transcriptome revealed 3,567 transcripts annotated as transcription factors (TF) belonging to 52 gene families. Expression profile analyses would allow to identify key TF for nodulation and SNF signaling / regulation.