Overexpression of maize chloride channel gene ZmCLC-d in Arabidopsis thaliana improved its stress resistance

Abstract

In plant cells, anion channels and transporters are essential for key functions. Members of the chloride channel (CLC) family located in intracellular organelles are required for anion accumulation, pH adjustment, and salt tolerance. Here, we cloned a maize (Zea mays L.) CLC gene, named ZmCLC-d, and found that its transcription was up-regulated under cold, drought, salt, and heat stresses, and after hydrogen peroxide (H 2 O 2 ) and abscisic acid (ABA) treatments. The overexpression of ZmCLC-d in Arabidopsis conferred tolerance to cold, drought, and salt stresses; this tolerance was primarily displayed by an increased germination rate, root length, plant survival rate, antioxidant enzyme (catalase, peroxidase, and superoxide dismutase) activities, and a reduced accumulation of Clin transgenic plants as compared with wild type (WT) plants. The accumulation of H 2 O 2 and superoxide anion in leaves of the ZmCLC-d-overexpressing plants is much less than that of the WT plants. The expressions of some stress related genes, such as CBF1, CBF2, CBF3, DREB2A, and RCI2A, increased to a greater extent in the ZmCLC-d-overexpressing plants than in the WT. Our results strongly suggest that ZmCLC-d played an important role in stress tolerance.

Molecular cloning and characterization of the chloride channel gene family in trifoliate orange

“…The CLCs were also suggested to contribute to plant salt-tolerance as their roles in mediating Cl -transport across the tonoplast (Nakamura et al 2006, Wong et al 2013, Wang et al 2015. Control of Cl -transport and Clexclusion from shoots contributes to salt tolerance in many species, such as wheat, barley, avocado, grapevine, and citrus (Teakle andTyerman 2010, Tregeagle et al 2010).…”

Genomics, Physiology, and Molecular Breeding Approaches for Improving Salt Tolerance

“…The possible involvement of other transporters in vacuole Na + sequestration has also been suggested (7). Cl − sequestration into the vacuole may be mediated by a member of the CLC family (155)(156)(157). (b) Partial ion homeostasis mechanisms for toxic (Na + and Cl − ) and beneficial (K + and Ca 2+ ) elements in the root.…”

“…Recent studies of tonoplast-localized GmCLC1 in soybean revealed that Cl − transport mediated by GmCLC1 is dependent on cytoplasmic pH (implying that this transporter functions as a Cl − /H + antiporter) and that overexpression of GmCLC1 throughout the entire Arabidopsis plant and in the hairy roots of soybean plants resulted in significantly lower Cl − accumulation in shoots during salt stress (156,159) (Figure 1). In addition, constitutive overexpression of CsCLC-c from trifoliate orange (Poncirus trifoliata) in the Arabidopsis atclc-c mutant and of ZmCLC-d from maize in the Arabidopsis atclc-d mutant rendered the mutants more salt tolerant, with decreased Cl − accumulation in the whole plant in comparison with nontransformants and wild-type plants (155,157). These studies suggest that CLC-type transporters play a beneficial role in Cl − exclusion during salt stress, presumably through Cl − sequestration in vacuoles.…”

Chloride on the Move

“…Tonoplast AtCLCc secretes Clinto root vacuoles and helps improve salt tolerance, and regulates gas exchange through its role in light induced opening and ABA-induced closure [74]; AtCLCg, localized to mesophyll tonoplast, is predicted to have a similar role for Clcompartmentation in leaf mesophyll as its knockout showed increased sensitivity to salt [75]. CLC have their expression upregulated by salt in rice, maize and citrus [80][81][82], and overexpression of tonoplast localized GmCLC1 in soybean increased its salt tolerance [83,84], indicating, again that direct transfer of Clis not the only factor controlling Cl --related tolerance in plants. For further information on other CLC members, which also localize to other endo-membrane, we refer readers to [85].…”