Transcriptional analysis between two wheat near-isogenic lines contrasting in aluminum tolerance under aluminum stress

Abstract

To understand the mechanisms of aluminum (Al) tolerance in wheat (Triticum aestivum L.), suppression subtractive hybridization (SSH) libraries were constructed from Al-stressed roots of two near-isogenic lines (NILs). A total of 1,065 putative genes from the SSH libraries was printed in a cDNA array. Relative expression levels of those genes were compared between two NILs at seven time points of Al stress from 15 min to 7 days. Fifty-seven genes were differentially expressed for at least one time point of Al treatment. Among them, 28 genes including genes for aluminum-activated malate transporter-1, ent-kaurenoic acid oxidase-1, beta-glucosidase, lectin, histidine kinase, and phospoenolpyruvate carboxylase showed more abundant transcripts in Chisholm-T and therefore may facilitate Al tolerance. In addition, a set of genes related to senescence and starvation of nitrogen, iron, and sulfur, such as copper chaperone homolog, nitrogen regulatory gene-2, yellow stripe-1, and methylthioribose kinase, was highly expressed in Chisholm-S under Al stress. The results suggest that Al tolerance may be co-regulated by multiple genes with diverse functions, and those genes abundantly expressed in Chisholm-T may play important roles in enhancing Al tolerance. The down-regulated genes in Chisholm-S may repress root growth and restrict uptake of essential nutrient elements, and lead to root senescence.

Quantitative Trait Loci and Crop Performance under Abiotic Stress: Where Do We Stand?: Table I.

“…Therefore, allelic differences in mRNA expression levels are likely to remain a very useful criterion when identifying candidate genes. Transcriptome profiling from model or target crop species can also be used to identify candidates (Giuliani et al, 2005a;Guo et al, 2007;Poroyko et al, 2007). However, the power of this information alone in QTL cloning is limited by the large number of genes that usually show expression differences related to stress treatment, genotype, or source tissue.…”

“…The systematic dissection of QTLs governing the naturally occurring variation relevant for crop yield and its sustainability will facilitate a more targeted and effective tailoring of cultivars with an improved performance under abiotic constraints (Baum et al, 2007;Dwivedi et al, 2007;Mackill, 2007;Xu and Crouch, 2008). Nonetheless, it is difficult to predict to what extent QTL-based MAS will affect breeding practices aimed at improving tolerance to abiotic stresses.…”

Gene expression profiling in soybean under aluminum stress: genes differentially expressed between Al-tolerant and Al-sensitive genotypes

“…Lipid transport proteins facilitate transport of lipids to cell walls for biosynthesis of cutin layers and surface waxes as a defense mechanism in response to pathogen attack [26]. They are also induced by abiotic stresses including aluminum stress in wheat roots [14]. A recent report by [27] suggests that lipid transport proteins loosen cell wall in a nonhydrolytic mode and enhance cell elongation, the role traditionally attributed to expansin.…”

“…The aim of the present work was to identify candidate soybean Al-tolerance genes using the Al-tolerant soybean PI 416937 and the Al-sensitive Young employing the technique of DNA microarrays to understand specific gene function related to Al tolerance trait. Such approach was recently used in wheat [14,15], maize [16], Medicago truncatula [17,18] and Arabidopsis [19] to discern the molecular basis of Al tolerance in the respective species.…”

Validation of quantitative trait loci for aluminum tolerance in Chinese wheat landrace FSW

“…An alternative method for evaluating Al tolerance using hydroponic culture provides a strict control in nutrient solution containing a toxic level of Al and pH, and can provide non-destructive measurements in large populations. Therefore, it has been widely used in genetic studies (Polle et al 1978;Ma et al 2006;Guo et al 2007;Navakode et al 2009). With this method, NRG of Al-stressed seedling has been measured to reflect plant tolerance to Al toxicity in several studies (Parker and Pedler 1998;Zhou et al 2007a).…”