Foliar Application of Y-Aminobutyric Acid (GABA) Improves Vegetative Growth, and the Physiological and Antioxidative Potential of Daucus Carota L. under Water Deficit Conditions

Abstract

Scarcity of water is one of the most serious concerns in plant biology with diverse implications at all the levels of molecular, biochemical, and physiological phenomena of plant growth, development, and consequently the productivity. Most of the strategies to induce or enhance drought tolerance in plants are unreasonably expensive and/or time-consuming. Some studies conducted in the recent past have shown that plant growth regulators (PGRs) may induce/improve physiological tolerance in plants to cope with adverse environmental conditions including drought. The present study was aimed at investigating the effects of foliar spray of GABA (0, 1, 2, and 4 mM) applied 20 days following the germination of seeds, on vegetative growth, morphological characteristics, integrity of cell-membrane, and the levels of photosynthetic pigments and enzymatic antioxidants in carrot cvs. Supertaj and Bharat, grown under 100% and 50% field capacity of soil moisture. The treated and untreated (control) carrot plants were harvested and analyzed 2 weeks following the GABA application. The results revealed that foliar application of GABA improved the vegetative growth and significantly increased the levels of free amino acids, plastid pigments, enzymatic antioxidants, and the relative water content in the root crop grown under 50% field capacity of soil moisture, compared to control. Additionally, the GABA application decreased the electrolyte leakage of ions and melondialdehyde (MDA) content in carrot leaves. The carrots harvested from GABA-treated or untreated (control) plants were not significantly different for their protein contents. In conclusion, the incorporation of GABA in the production management of carrots may help plants to mitigate the adverse effects of water deficit stress.

Physiological and Biochemical Characterization of the GABA Shunt Pathway in Pea (Pisum sativum L.) Seedlings under Drought Stress

“…The GABA shunt has been associated with physiological responses, such as cytosolic pH regulation [86], nitrogen metabolism, and carbon fluxes into the Krebs cycle [87], protection against ROS production [88], and osmoregulation and signaling [89]. The GABA shunt is also involved in carbon and nitrogen metabolism, maintenance of cell membrane integrity [90], and minimizing the negative effects of abiotic stresses on plant metabolism [91].…”

“…Similarly, Tatar and Gevrek [135] reported an increase in the level of MDA in wheat as the duration of drought stress increased. Leaves of growing carrots (Daucus carota L.) accumulated high levels of MDA content under water deficit stress [91]. Morabito and Guerrier [136] reported that oxidative stress occurred 12 h after the application of drought stress.…”

Quantitative measurement of internal quality of carrots using hyperspectral imaging and multivariate analysis

“…Develop simplified LS-SVM and PLSR models. 5. Use the best model to predict the quality attributes of each sample pixel and compare its performance to Fig.…”