Salicylic acid involved in the process of aluminum induced citrate exudation in Glycine max L.

Abstract

Background and aims Aluminum (Al)-induced citrate exudation has been identified as an important Alresistance mechanism in soybean. Salicylic acid (SA) is a crucial signal molecule modulating numerous environment stresses in plants. This study was to investigate the role of SA in Al-induced citrate exudation from soybean roots. Methods HPLC was used to test the Al-induced endogenous SA changes, effect of exogenous SA / an inhibitor of SA biosynthesis paclobutrazol (PAC) on Al-induced citrate efflux. The activity / transcriptional expression of mitochondrial aconitase (ACO) and a putative citrate transporter gene Gm-MATE1 were examined by an enzyme method or qRT-PCR. Results Al stress caused increase of endogenous free-SA and conjugated SA (SAG). Exogenous SA enhanced the amount of Al-induced citrate secretion from roots, decreased the Al accumulation in root apices and alleviated the Al-induced inhibition of root elongation. PAC decreased the Al-induced enhancement of endogenous free SA and reduced the amount of citrate exudation. SA and Al together treatment further decreased mitochondrial aconitase (ACO) activity and enhanced the transcriptional expression of Gm-MATE1compared to the sole Al treatment. Conclusions Al-induced SA production may act as an early signal to regulate the metabolism and transportation of citrate in soybean roots.

The interaction of salicylic acid and Ca2+ alleviates aluminum toxicity in soybean (Glycine max L.)

“…Shakirova et al (2003) found that when wheat is pre-treated with SA, there is remarkable alleviation in the salinity-induced inhibition of root elongation. We previously reported that exogenous SA could increase endogenous SA under Al stress (Liu et al, 2012). In this study, we found that SA significantly suppressed Al stress-induced inhibition of root growth and Alaccumulation.…”

“…Liu et al (2012) reported that Al induces the accumulation of free-SA and SAG; however, the exogenous SA not only alleviates Al-induced inhibition of root elongation but also reduces the accumulation of Al in soybean roots. Chen et al showed that Ca 2þ is able to regulate both intracellular and extracellular transportation of SA (Chen and Kuc, 1999).…”

“…Plants combat Al toxicity by external exclusion and internal detoxification (Kochian, 1995). Several signaling molecules, including Ca 2þ , abscisic acid (ABA), and SA are shown to alleviate Al toxicity (Liu et al, 2012).…”

“…Emerging evidence has shown that SA plays an important role in Al tolerance. For example, SA reduces Al uptake in soybean roots under Al stress and suppresses Al-induced inhibition of root elongation (Liu et al, 2012). Kawano et al (1998) discovered that when a suspension of tobacco cells is treated with SA, the concentration of superoxide anions increases in a rapid and transient manner.…”

Role of the plasma membrane H+-ATPase in the regulation of organic acid exudation under aluminum toxicity and phosphorus deficiency

“…7,12 The exudation of organic acids is mediated by membranelocalized organic acids transporters, which belong to 2 families, ALMT (Al-activated malate transporter) and MATE (multidrug and toxic compound extrusion). Several genes encoding ALMT1 and MATE-family proteins have been identified from the roots of wheat, 13 Arabidopsis, 14 sorghum, 15 rice bean, 16 soybean, 17,18 and alfalfa, 19,20 And the identification and function of organic transporter genes in plant resistance to Al stress have been widely reviewed. [21][22][23] Beside on Al-induced organic acids transporter gene's expression, plasma membrane H C -ATPase is also involved in Al-induced organic acid process.…”