Physiological Responses of Wheat to Drought and Antitranspirants and Transcriptomic Changes in Anthers

Sehar, M. (2025) Physiological Responses of Wheat to Drought and Antitranspirants and Transcriptomic Changes in Anthers. Doctoral thesis, Harper Adams University.

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Abstract

Climate change is affecting wheat production, prompting scientists to find alternative ways to improve drought tolerance. Antitranspirants applied at the critical growth stages of wheat have shown promising results in conserving water and improving crop yield in various studies, possibly by enhancing pollen viability. However, the molecular mechanisms behind these improvements are not yet well understood. Therefore, in this thesis, two field experiments (in rain shelters), one glasshouse experiment and the transcriptomic study of early meiotic anthers (leptotene-zygotene), were conducted to understand the effects of the film (Vapor Gard (VG), di-1-p-menthene) and metabolic (Abscisic acid (ABA), 20% S-ABA) antitranspirants at different growth stages: VG at stem elongation (GS31), VG or ABA before the start of meiosis (GS39) and ABA at grain filling stage (GS71-73). Field and the glasshouse experiments revealed no significant effects from antitranspirants, assessed via different physiological parameters (mainly relative water content, pollen viability, yield and most of the yield components) when droughted unsprayed and antitranspirants sprayed plants were compared. The main reason for this might be low soil moisture levels when antitranspirants were applied. However, significant variations at the gene expression level were observed in anthers, and most of the differentially expressed genes (DEGs) were downregulated under drought stress and applying antitranspirants further downregulated these genes (3,959 downregulated genes in both VG and ABA samples), with fewer upregulated genes (830 genes). The number of downregulated genes was higher in VG-treated plant anthers (3,325 genes) compared to ABA-treated anthers (634 genes). DEGs involved in biological processes, especially related to carbohydrate/sugar metabolism, were mainly affected. Overall, the results suggest that plants are more sensitive to antitranspirants at the molecular level as observed in anthers, than at the whole plant level, and less severe drought stress may be needed for the altered gene expression responses to significantly impact crop yield.

Item Type:	Thesis (Doctoral)
Divisions:	Agriculture and Environment (from 1.08.20)
Depositing User:	Mrs Susan Howe
Date Deposited:	02 Dec 2025 10:06
Last Modified:	02 Dec 2025 10:06
URI:	https://hau.repository.guildhe.ac.uk/id/eprint/18275

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