Soybean GmbZIP44, GmbZIP62 and GmbZIP78 genes function as negative regulator of ABA signaling and confer salt and freezing tolerance in transgenic Arabidopsis

Abstract

From soybean plant, 131 bZIP genes were identified and named as GmbZIPs. The GmbZIPs can be classified into ten groups and more than one third of these GmbZIPs are responsive to at least one of the four treatments including ABA, salt, drought and cold stresses. Previous studies have shown that group A bZIP proteins are involved in ABA and stress signaling. We now chose four non-group A genes to study their features. The four proteins GmbZIP44, GmbZIP46, GmbZIP62 and GmbZIP78 belong to the group S, I, C and G, respectively, and can bind to GLM (GTGAGTCAT), ABRE (CCACGTGG) and PB-like (TGAAAA) elements with differential affinity in both the yeast one-hybrid assay and in vitro gel-shift analysis. GmbZIP46 can form homodimer or heterodimer with GmbZIP62 or GmMYB76. Transgenic Arabidopsis plants overexpressing the GmbZIP44, GmbZIP62 or GmbZIP78 showed reduced ABA sensitivity. However, all the transgenic plants were more tolerant to salt and freezing stresses when compared with the Col plants. The GmbZIP44, GmbZIP62 and GmbZIP78 may function in ABA signaling through upregulation of ABI1 and ABI2 and play roles in stress tolerance through regulation of various stress-responsive genes. These results indicate that GmbZIP44, GmbZIP62 and GmbZIP78 are negative regulators of ABA signaling and function in salt and freezing tolerance.

An R2R3-type transcription factor gene AtMYB59 regulates root growth and cell cycle progression in Arabidopsis

“…The transcriptional activation ability was also examined in Arabidopsis protoplast system according to our previous report [41]. A plasmid containing 5X UAS and 35S promoter upstream of a reporter gene encoding a firefly luciferase (LUC) was used as a reporter.…”

Comparative Transcriptome Analysis of Two Olive Cultivars in Response to Nacl Stress

“…Chondrolia Chalkidikis and module-9 in cv. Kalamon [45][46][47][48][49]. In addition, a third TF, NF-YC (se023_D5), appeared also as a co-regulator for stress-related module-9 in cv.…”

Molecular Responses to Osmotic Stresses in Soybean

“…Surprisingly, GmERF3 and GmERF4 impose opposite effect on the expression of biotic and abiotic stress responsive genes (PR1, PR2, PR4, osmotin and SAR8.2) in transgenic tobacco, suggesting that they may function in different branches of osmotic stress signalling cascade (Zhang et al, 2009a;Zhang et al, 2009b). bZIP Expression of ABRE/ABF regulon is regulated by basic leucine zipper (bZIP) transcription factors in plants (Liao et al, 2008a;Liao et al, 2008c). Nearly 150 bZIP transcription factors have been annotated from the soybean genome (Mochida et al, 2009), in which nearly one third of them are induced under ABA, salt, drought, and/or cold stresses (Aoki et al, 2005;Liao et al, 2008a;Liao et al, 2008c).…”

“…bZIP Expression of ABRE/ABF regulon is regulated by basic leucine zipper (bZIP) transcription factors in plants (Liao et al, 2008a;Liao et al, 2008c). Nearly 150 bZIP transcription factors have been annotated from the soybean genome (Mochida et al, 2009), in which nearly one third of them are induced under ABA, salt, drought, and/or cold stresses (Aoki et al, 2005;Liao et al, 2008a;Liao et al, 2008c). SGBF-1 and SGBF-2 are two bZIP homologues cloned from soybean that are induced by cold and ABA, and SGBF-1 has been shown to interact with a C 2 H 2 -type zinc finger protein, SCOF-1 (Kim et al, 2001b); and yet there is no evidence showing the direct involvement of these two proteins in osmotic stress response.…”