Expression of an apoplast‐localized BURP‐domain protein from soybean (GmRD22) enhances tolerance towards abiotic stress

Abstract

The BURP-domain protein family comprises a diverse group of plant-specific proteins that share a conserved BURP domain at the C terminus. However, there have been only limited studies on the functions and subcellular localization of these proteins. Members of the RD22-like subfamily are postulated to associate with stress responses due to the stress-inducible nature of some RD22-like genes. In this report, we used different transgenic systems (cells and in planta) to show that the expression of a stress-inducible RD22-like protein from soybean (GmRD22) can alleviate salinity and osmotic stress. We also performed detailed microscopic studies using both fusion proteins and immuno-electron microscopic techniques to demonstrate the apoplast localization of GmRD22, for which the BURP domain is a critical determinant of the subcellular localization. The apoplastic GmRD22 interacts with a cell wall peroxidase and the ectopic expression of GmRD22 in both transgenic Arabidopsis thaliana and transgenic rice resulted in increased lignin production when subjected to salinity stress. It is possible that GmRD22 regulates cell wall peroxidases and hence strengthens cell wall integrity under such stress conditions.

Differential Impact of Acclimation and Acute Water Deprivation in the Expression of Key Transcription Factors in Soybean Roots

“…In Arabidopsis, the AREB1/ABF gene controls the expression of the AtRD20 gene, while the MYB2 and MYC2 genes function as transcriptional activators in abscisic acid signaling and also activate directly the expression of AtRD22 gene (Abe et al 2003;Wang et al 2012). Besides, DREB2A controls the expression of AtRD29A (Narusaka et al 2003).…”

Cell water content and lignification in maize regulated by rhizobacteria under salinity

“…In this study, both lignin and lignin monomer increased in inoculated plants, both in normal and salinity state. Recently, Wang et al (2012), has reported that transgenic rice line deposited enhanced levels of lignin when exposed to salt treatment are more tolerant than its wild type. Martinez et al (2004) reported that the highest accumulation of lignin monomers was observed in the plants treated with P. aeruginosa.…”

“…Three hundred mg of leaves samples from each treatment were homogenized in 6.5 mL Tris-HCl buffer at pH 8.8 containing 15 mM of β-mercaptoethanol and centrifuged at 12,000 rpm for 30 min to obtain the supernatant used for enzyme activity assay (Wang et al, 2012). 1 mL of the extraction buffer, 0.5 mL of 10 mM L-phenylalanine (ME -1.07256), 0.35 mL of double distilled water and 0.15 mL of enzyme extract were incubated for 1 h at 37 °C in a water bath and the reaction was stopped by adding 0.5 Jha Braz.…”

“…But lignification of plant tissues is a composite process involving numerous types of phenolic substrates and enzymes (Wang et al, 2013). To avoid cell wall damage of plants, when plants are exposed to water stress it occur naturally in early stage of development (Moura et al, 2010) and under stress cell wall lignin content and arrangement it changes (Cabane et al, 2012).…”

Transcriptome profiling of peanut (Arachis hypogaea) gynophores in gravitropic response

“…Also, abscisic acid (ABA) and salt stress can induce RD22 expression (Iwasaki et al 1995;Abe et al 1997). Recently, it has been reported that transgenic expression of a RD22-like protein (GmRD22) can reduce salinity and osmotic stress in plants (Wang et al 2012). Both downregulated expression of RD22-like protein at 6 and 12 h in the gynophores with pointing upward indicate its opposite role in gravitropism, but how the RD22-like protein functions in gravitropism needs further investigation.…”