A Soybean Beta-Expansin Gene GmEXPB2 Promotes Phosphate Status-Dependent Root Development

摘要

A cDNA clone, GmEXPB2, was isolated from long-term phosphate (Pi) starvation-induced subtractive library. After cloning of full-length cDNA, the subsequent bioinformatics analyses revealed homology of the protein coded by the identified gene to the β-expansin (EXPB) family. Using TAIL-PCR strategy, a 1500-bp-long promoter fragment was cloned. Quantitative PCR analysis indicated that GmEXPB2 was root-abundant expressed and related to Pi efficiency closely. Transgenic hairy roots expressing promoter::GUS constructs showed that GmEXPB2 is preferentially expressed in the pericycle cells and root caps, implying that GmEXPB2 might be involved in the development of the lateral roots and primary roots.