Long-distance ABA transport can mediate distal tissue responses by affecting local ABA concentrations

Abstract

Environmental stresses that perturb plant water relations influence abscisic acid (ABA) concentrations, but it is unclear whether long-distance ABA transport contributes to changes in local ABA levels. To determine the physiological relevance of ABA transport, we made reciprocal-and self-grafts of ABA-deficient flacca mutant and wild-type (WT) tomato plants, in which low phosphorus (P) conditions decreased ABA concentrations while salinity increased ABA concentrations. Whereas foliar ABA concentrations in the WT scions were rootstock independent under control conditions, salinity resulted in longdistance transport of ABA: flacca scions had approximately twice as much ABA when grafted on WT rootstocks compared to flacca rootstocks. Root ABA concentrations were scion dependent: both WT and flacca rootstocks had less ABA with the flacca mutant scion than with the WT scion under control conditions. In WT scions, whereas rootstock genotype had limited effects on stomatal conductance under control conditions, a flacca rootstock decreased leaf area of stressed plants, presumably due to attenuated root-to-shoot ABA transport. In flacca scions, a WT rootstock decreased stomatal conductance but increased leaf area of stressed plants, likely due to enhanced root-to-shoot ABA transport. Thus, long-distance ABA transport can affect responses in distal tissues by changing local ABA concentrations.

Genomic Organization and Comparative Phylogenic Analysis of NBS-LRR Resistance Gene Family in Solanum pimpinellifolium and Arabidopsis thaliana

“…[32][33][34][35][36][37][38][39][40] Depending on the plant stage and duration of the stress, abiotic stress causes serious yield loss. [41][42][43][44][45][46] Furthermore, compared with these gene-related abiotic stresses, which are induced widely by exogenous hormones and abiotic stress factors, [47][48][49][50][51][52][53][54][55][56][57][58][59][60] plant NBS-LRR resistance genes are rarely induced. Usually, although several wild tomato species have stress tolerance genes, it is very difficult to transfer them into cultivars due to high genetic distance and crossing barriers.…”

Molecular Mechanism for the Regulation of ABA Homeostasis During Plant Development and Stress Responses

“…When the roots of plants are placed in a solution containing ABA, an increased ABA content is detected in leaves [ 53 ], implying that ABA can be transported from root to shoot. A previous point of view supposed that the root was only place for ABA synthesis and ABA was transported over a long distance to leaves [ 53 ]. The recent discovery of several ABA transporters strongly supports the idea that ABA is indeed transported by specific transporters and that it is transported in whole plant.…”

Sugar transporter proteins in Capsicum: identification, characterization, evolution and expression patterns

“…Phytohormones, such as ABA, IAA and GA, are involved in various stress signaling pathways, and play significant roles in alleviating adverse abiotic stresses in plants, along with multiple other biological functions [67][68][69][70][71][72][73]. To elucidate the potential functions of CaSTP genes in response to exogenous phytohormones, we analysed available data about the expression profiles of CaSTP genes in leaves and roots treated with these exogenous substances (Figure 8).…”