PvTRX1h Gene Involved in Regulation of Nodules in Common Bean

The legume-rhizobium symbiotic relationship has been widely studied and characterized. However, little information is known on the role of histone lysine methyltransferases in this interaction and in the formation of nodules in the common bean.

A study by the team of Aarón Barraza from Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional aimed to understand the mechanism of nodulation control in common bean (Phaseolus vulgaris). The team focused on the role of PvTRX1h, a histone lysine methyltransferase coding gene, in nodule development, and auxin biosynthesis. Using reverse genetics approach, the team generated common bean with knocked-down PvTRX1h expression.

Downregulation of PvTRX1h increased the number of nodules per plant, but reduced the number of colony-forming units recovered from nodules. Further analysis found that genes involved in the synthesis of indole-3-acetic acid were upregulated. PvTRX1h downregulation also altered starch accumulation.

Based on these results, PvTRX1h likely alters the auxin signaling network to determine bacterial colonization, nodule number, starch accumulation, hormone levels, and cell proliferation in common bean.

For more information, read the article in Plant Science.