Citrate transporters play an important role in regulating aluminum-induced citrate secretion in Glycine max

Abstract

To further understand the process of Al-induced citrate secretion from soybean roots, the effect of protein synthesis inhibitor, anion channel blockers, and citrate carrier inhibitors on Al-induced citrate exudation was investigated in Al-resistant soybean cultivar PI 416937. Citrate exudation from roots increased with the increase of Al concentration from 10 to 50 µM and initiated after 4 h of Al exposure. Protein synthesis inhibitor, cycloheximide (CHM; 25 µM) completely inhibited Al-induced citrate secretion during 12-h exposure, suggesting that novel protein synthesis was necessary in Al-induced citrate efflux. Also both anion channel blocker anthracene-9-carboxylic acid (A-9-C) and citrate carrier inhibitor mersalyl acid (Mersalyl) significantly reduced citrate secretion, suggesting that both anion channels in plasma membrane and citrate carriers in mitochondria membrane were the rate limiting factors of Al dependent citrate release. However, Al-induced citrate secretion was insensitive to anion channel blockers phenylglyoxal (PG), 4,4'-diisothiocyanostibene-2,2'-disulfonat (DIDS) and citrate carrier inhibitor pyridoxal 5'-P (PP).Additional key words: aluminum stress, soybean, anion channel blockers, citrate carrier inhibitors.

Mechanistic studies of perfluorooctane sulfonate, perfluorooctanoic acid uptake by maize (Zea mays L. cv. TY2)

“…1 μmolL −1 AgNO 3 or 1 mmolL −1 glycerol was used as aquaporin inhibitors (Kong et al 2007). 10 μmolL −1 anthracene-9-carboxylic acid (9-AC, Aladdin Chemistry, Co. Ltd, China), or 5 μmolL −1 4,4′-diisothiocyanostibene-2,2′-disulfonate (DIDS, Tokyo Chemical Industry, Co. Ltd, Japan), or 5 μmolL −1 5-nitro 2-(3-phenylpropylamine) benzoic acid (NPPB, Tokyo Chemical Industry, Co. Ltd, Japan) was used as anion channel inhibitors (You et al 2010;Matveyeva et al 2003). Maize seedlings were transferred to 400 mL nutrient solution containing 1.0 mgL −1 PFOS or PFOA with metabolic or aquaporin or anion-channel inhibitors.…”

Roles of Organic Acid Anion Secretion in Aluminium Tolerance of Higher Plants

“…As early as 1995, Ryan et al observed that inhibitors of anion channels inhibited the Al-activated secretion of malate from wheat roots, providing evidence that Al might activate malate secretion via a channel in the PM in the apical cells of Al-tolerant wheat cells [37]. Increasing evidence shows that the influence of anion channel inhibitors on the Al-activated secretion of OA anions depends on the species of OA anions secreted, plant species, inhibitor concentration, and species (see [13, 30, 37, 62], Table 1). Li et al observed that two citrate carrier inhibitors (pyridoxal 5′-phosphate (PP) and phenylisothiocyanate (PITC)) effectively inhibited citrate secretion, meaning that the Al-activated citrate from rye roots is mediated by citrate carrier [21].…”