Identification of differentially expressed genes by cDNA‐AFLP technique during heat stress in cowpea nodules

Abstract

Legume nodules formed by diazotrophic microorganisms are active sites for biological nitrogen fixation (BNF). In tropical regions, a significant part of N supply for soybean, peanut and bean crops is derived from BNF, which is nevertheless often limited by high temperature stress. In contrast, cowpea nodules are very resistant to high temperatures. To understand the molecular bases of thermotolerance during BNF under heat stress, we have used cDNA-amplified fragment length polymorphism experiments to identify differentially expressed transcripts from cowpea nodules subjected to heat shock treatment. The expression profiles obtained showed approximately 600 bands, 55 up-regulated and nine corresponding to genes repressed by heat stress. Twenty transcript-derived fragments were isolated, cloned and sequenced. The Vigna unguiculata nodule and stress response transcripts present similarities to those that encode low molecular weight heat shock proteins, wound-induced proteins, disease resistance protein, and xylan endohydrolase isoenzyme, as well as different housekeeping genes. The differential expression of 15 genes was confirmed by using Northern blot or reverse Northern hybridization experiments. ß

Expressão gênica induzida por estresses abióticos em nódulos de feijão-caupi

“…Nessas condições, o metabolismo de lipídeos da membrana é alterado e apresenta função importante na aclimatação ao estresse (Gigon et al, 2004). Torres-Franklin et al (2007) também observaram acúmulo de DGDG em feijão-caupi em resposta ao deficit hídrico. Em plantas de Arabidopsis thaliana submetidas ao deficit hídrico, foram relatadas alterações no metabolismo de lipídeos de membrana em folhas (Gigon et al, 2004).…”

“…Em plantas de Arabidopsis thaliana submetidas ao deficit hídrico, foram relatadas alterações no metabolismo de lipídeos de membrana em folhas (Gigon et al, 2004). Embora esse galactosilglicerolipídeo esteja associado, principalmente, ao cloroplasto, verificouse seu acúmulo em membranas não cloroplásticas em resposta ao estresse, o que indica sua participação nos mecanismos de tolerância da planta ao deficit hídrico (Torres-Franklin et al, 2007).…”

empty pericarp2 Encodes a Negative Regulator of the Heat Shock Response and Is Required for Maize Embryogenesis

“…These data indicate that embryo abortion in emp2 mutant embryos is caused by unattenuated HSR. The HSR is known to result in transcriptional and translational arrest of numerous plant genes (reviewed by Nagao et al, 1986;Morimoto, 1991;Vierling, 1991), including those that affect cellular metabolism (Simoes-Araujo et al, 2002) and cell wall/membrane biosynthesis (Li and Showalter, 1996;Iwahashi and Hosoda, 2000;Simoes-Araujo et al, 2002). In addition, the HSR blocks essential cellular processes such as DNA synthesis and cell cycle progression (Song et al, 2001, and references therein).…”

Sinorhizobium meliloti nifA mutant induces different gene expression profile from wild type in Alfalfa nodules

“…Since its first application on potato tuber development, several modifications of this technique have improved its validity and advantages over other fingerprinting techniques and DNA chip-based approaches [18][19][20]. In most cases, it has been employed for surveying transcriptional changes in host plants during interactions with fungi, bacteria, nematode or environmental stimuli [21][22][23][24][25][26][27][28][29]. In this study, cDNA-AFLP was successfully used to identify 37 differentially expressed host plant genes in Alfalfa nodules.…”