ABA Alleviates Uptake and Accumulation of Zinc in Grapevine (Vitis vinifera L.) by Inducing Expression of ZIP and Detoxification-Related Genes

Abstract

Abscisic acid (ABA) is a plant hormone that can mitigate heavy metal toxicity. Exogenous ABA and ABA mimic 1 (AM1) were applied to study the influence on Zn uptake and accumulation in Vitis vinifera L. cv. Merlot seedlings exposed to excess Zn. The seedlings were treated with either normal or excess levels of Zn in combination with applications of ABA and AM1. Excess Zn exposure resulted in decreased lateral root length, decreased photosynthesis, elevated uptake, and accumulation of Zn in roots, trunks, and stems, decreased jasmonic acid content in roots and leaves, and induced the expression of Zn transportation- and detoxification-related genes. Remarkably, in the presence of toxic amounts of Zn, the exogenous application of ABA, but not of AM1, reduced the uptake and accumulation of Zn in roots and induced higher expression of both ZIP genes and detoxification-related genes in root and leaf. These results indicate that exogenous ABA enhances the tolerance of grape seedlings to excess Zn and that AM1 is not a suitable ABA mimic compound for Zn stress alleviation in grapes.

Effects of Rootstocks on Blade Nutritional Content of Two Minority Grapevine Varieties Cultivated under Hyper-Arid Conditions in Northern Chile

“…However, blades collected in the 2018-19 season presented deficiencies in Zn levels (Table 4). Zn is an essential micronutrient for plants that plays a key role in photosynthetic redox reactions, and it is an essential cofactor for many enzymes involved in nitrogen metabolism and protein synthesis [39,40]. Zn solubility is strongly dependent on pH, and similar to Fe, Zn availability is low in calcareous soils with a pH > 7 and high bicarbonate content [40].…”

“…Zn is an essential micronutrient for plants that plays a key role in photosynthetic redox reactions, and it is an essential cofactor for many enzymes involved in nitrogen metabolism and protein synthesis [39,40]. Zn solubility is strongly dependent on pH, and similar to Fe, Zn availability is low in calcareous soils with a pH > 7 and high bicarbonate content [40]. Zn deficiency may alter the expression and function of proteins at metabolic level that results in different physiological symptoms characterized by root apex necrosis, and in a decline in starch production and sugar accumulation in leaves [40,41].…”

“…Zn solubility is strongly dependent on pH, and similar to Fe, Zn availability is low in calcareous soils with a pH > 7 and high bicarbonate content [40]. Zn deficiency may alter the expression and function of proteins at metabolic level that results in different physiological symptoms characterized by root apex necrosis, and in a decline in starch production and sugar accumulation in leaves [40,41]. Severe Zn deficiency in grapevines may result in the production of clusters with few berries that also vary in size from normal to very small [42,43].…”

“…Zn applications in grapevines cultivated under drought conditions enhance acquisition of many plant nutrients, promoting the vegetative and generative developments related to shoot and leaf growth, greener leaves, enhancing berry development and vine yield [44]. Furthermore, abscisic acid alleviates uptake and accumulation of Zn in grapevines by inducing expression of ZIP and detoxification-related genes [40]. Thereby, Zn absorption and accumulation in blades may be affected by high temperatures and drought conditions in grapevines cultivated under the hyper-arid conditions of Northern Chile.…”

Impact of Pb on Chlamydomonas reinhardtii at Physiological and Transcriptional Levels

“…These studies further indicated that the up-regulation of genes encoding C 2 H 2 , AP2, MYB, bHLH, and YABBY transcription factors in this study might have positively effects in the mechanism of Pb stress tolerance, through increasing the activity of CAT, POD, and SOD, enhancing the production of MDA and the sequestration of Pb. However, owing to some other transcription factors, including bZIP, SBP, and HB-other transcription factors were reported to involve in uptake and accumulation of trace elements, they might have negative effect on the regulation of Pb stress (Song et al, 2019).…”