Tehnoloogiainstituut

Permanent URI for this communityhttps://hdl.handle.net/10062/42114

Browse

Browsing Tehnoloogiainstituut by Subject "ABA"

Filter results by typing the first few letters
Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Search for missing components in high VPD-induced stomatal closure pathway
    (Tartu Ülikool, 2024) Morozova, Daana; Merilo,Ebe, juhendaja; Tartu Ülikool. Loodus- ja täppisteaduste valdkond; Tartu Ülikool. Tehnoloogiainstituut
    Climate warming is associated with rising atmospheric Vapour Pressure Deficit (VPD), which affects plant physiology and production. Some proteins in the high VPD-induced stomatal closure pathway are known (e.g., protein kinase OST1), but there are still missing components. To address this knowledge gap, the study aimed to investigate Arabidopsis mutants defective in selected genes in order to reveal new elements that might be involved in VPD-induced stomata closure. Mutants were selected based on Wang et al. (2020) table of OST1 putative substrates and the expression levels of these genes in guard cells versus mesophyll cells. Experiments were conducted using a gas exchange measurement device to study plants’ stomatal conductance in response to high VPD and a plant stress hormone - abscisic acid (ABA). The study results showed no statistically significant differences in the steady-state stomata conductance and closure responses among mutants and wild-type, suggesting that these genes are not involved in VPD-induced stomata closure. Therefore, more studies are needed to reveal the missing components in the stomatal high VPD-induced closure pathway above OST1. Current results still add knowledge about stomatal behavior in future climatic conditions.
  • Thumbnail Image
    Item
    The function of ABA transporters during low humidity-induced stomatal closure in Arabidopsis thaliana.
    (2021) Hasanov, Turgay
    Plants are important for our nature and for all living things. These organisms can produce food, energy and several natural products from carbon dioxide and solar energy. Plants take up CO2 from the air in exchange for water via small pores called stomata on the leaf surface. These stomata are formed by pairs of cells, called guard cells. As plants are sessile organisms, they cannot move and need to adapt their physiology to the imposed environmental conditions. Drought is one of the major problems caused by climate change and guard cell physiology plays an important role in regulating stomatal apertures and the plant water content. For stomatal aperture regulation under limiting water conditions, the plant hormone abscisic acid (ABA) plays a major role. To understand guard cell physiology and the role of ABA in the plant response to low air humidity, defined as the Vapor Pressure Deficit (VPD) between plants and the atmosphere, we performed gas exchange analyses using Arabidopsis thaliana wild type plants and mutants in which ABA transporter genes were disrupted. Among the tested mutants, we observed a slower VPD response in a mutant in which the ABCG22 gene was disrupted. However, we did not observe clearly altered high VPD responses of abcg25, abcg31, abcg40, npf4.6 and npf5.2 ABA transporter mutants. This may be due to a high functional overlap between several ABA transporter genes. We also performed gene expression analyses of ABA transporter genes using the Genevestigator tool. This allowed us to propose the testing of additional ABA transporter genes that might be relevant for the high VPD response in Arabidopsis.