Isolation and characterization of a new defense gene from soybean

Abstract

A cDNA clone of a single-copy gene designated SbPRP was isolated and characterized from 2-week-old soybean seedlings. It putatively encodes a bimodular protein similar to developmentally regulated proteins in other plant species. The deduced amino acid sequence consists of 126 amino acids with a distinct proline-rich domain (17 amino acids) and a long hydrophobically cysteine-rich domain (84 amino acids), plus a signal peptide of 25 amino acids in N terminal. SbPRP mRNA transcripts accumulated in an organ specific manner. It can be detected in leaves and epicotyls of soybean seedlings, whereas virtually expression signal of SbPRP was not detected in cotyledons, hypocotyls and roots. Further Northern hybridization suggested that SbPRP steady-state mRNA level accumulated differentially not only in response to salicylic acid, but to the inoculation of soybean mosaic virus Sa strain. Also it was responsive to drought treatment and salt (NaCl) stress. Therefore it is likely that SbPRP functions as a defense gene in soybean.

A soybean gene encoding a proline-rich protein is regulated by salicylic acid, an endogenous circadian rhythm and by various stresses

“…One group contains a regulatory gene that is generally involved in the signal transduction process (Zhang and Klessig 1997;Komjanc et al 1999;Sakamato et al 1999). Another group contains functional genes that possibly play roles in stress tolerance or defense reaction (Metraux et al 1988;Merkouropoulos et al 1999;Zhang et al 1999;Li and Chen 2000;He et al 2001a). Although some of the upstream and downstream genes have been well-studied and their association established, more genes need to be characterized to facilitate the full-understanding of plant responses to changes in their living conditions.…”

“…Recently, a fulllength gene from soybean has been cloned and showed homology to the tobacco mosaic virus resistance gene N. This gene has been mapped to the L linkage group using a genetic map established from a RIL population (He et al, unpublished results; Wu et al, unpublished results) and two of its homologs have been mapped to the J and F linkage groups (He et al 2001b). A mitochondrial atp6 gene was also characterized and it may play a role in the defense response (He et al 2001a). Although some of the genes related to defense or abiotic stress have been isolated, genes that may function in both defense and abiotic stress responses were less investigated.…”

Over‐expression of the water and salt stress‐regulated Asr1 gene confers an increased salt tolerance

“…Proline-rich proteins are known to be induced in response to biotic and abiotic stresses, including salinity ( Fig. 7 panel 2) (see Chai et al 1998;He et al 2001). The Phaseolus vulgaris stress-related, proline-rich protein PvSR1 was suggested to have a role in maintaining cellular integrity by forming a strong linkage with the cell wall (Chai & Zhang 1999).…”

Biologically Active Constituents of Soybean

“…It responded to drought treatment and salt stress. It appears that SbPRP plays a defense role in soybean [29].…”