Effect of exogenously applied kinetin and glycinebetaine on metabolic and yield attributes of rice (Oryza sativa L.) under drought stress

Abstract

Drought is one of the major abiotic stress responsible for yield reduction of crops worldwide. Kinetin (KIN) and glycine betain (GB) have an essential role in regulating cell division during the early phase of grain setting; assimilate flow and osmotic adjustment under drought stress. Effects of exogenously applied kinetin and glycine betain on some metabolic and yield attributes of two rice (Oryza sativa L.) cultivars viz., Basmati-385 and KS-282 were evaluated under water stress. KIN and GB were applied by spraying the plants at flowering stage before drought stress treatment. Both treatments significantly increased proline concentration in leaves and panicles of both the rice cultivars as compared to their control. They also increased soluble sugar in the leaves and panicles under water stress. Starch concentration in leaves and panicles of both the rice cultivars were increased significantly (p<0.05) by KIN and GB spray. However, the magnitude of increase of the starch in panicles was more pronounced in cv. Basmatti-385 than cv. KS-282. Under the applied water stress both KIN and GB spray significantly increased paddy yield in both the rice cultivars. Both KIN and GB spray significantly increased the number of seeds per panicle in both the rice cultivars. The quantitative increase in paddy yield and seed number was greater in cv. Basmatti-385 as compared to cv. KS-282. Exogenous application of KIN at flowering stage could be used as an effective treatment to mimic the adverse effects of water stress in fine rice cultivars.

Exogenous Kinetin Promotes the Nonenzymatic Antioxidant System and Photosynthetic Activity of Coffee (Coffea arabica L.) Plants Under Cold Stress Conditions

“…The kinetin-hydrogen peroxide-mediated reinforcement of the antioxidant system is supported by high amounts of antioxidant compounds analyzed in the current study (Figures 3-5). The current results are in agreement with several reports were exogenous kinetin treatment increased the tolerance of plants to abiotic stress conditions through the increased activities of antioxidant enzymes [34][35][36]52], as well as the increased contents of several antioxidant compounds, such as flavonoids, gibberellins, salicylic acid, jasmonic acid and abscisic acid in salinity-stressed soybean plants [37], proline in drought-stressed rice [39], salvianolic acid and rosmarinic acid in Dracocephalum forrestii [40]. Although the accumulation of several secondary metabolites in the leaves of coffee plants under oxidative stress conditions is a well-known phenomenon [15,16], this study is the first to report a profound increment in the contents of these compounds in response to exogenous kinetin treatment under optimal or cold stress conditions.…”

“…Basing on related works [29,34,39,46], it was presumed that the concentration of kinetin used in the current study would have significant physiological effects on the coffee plants. Foliar sprays were administered three times every after 3 days, using a hand sprayer immediately after the growth chamber lights were routinely turned off.…”

“…Although the mechanism of kinetin action in mitigating oxidative stresses is not yet clearly understood, it has been suggested that kinetin upregulates both the enzymatic and the nonenzymatic antioxidative systems, hence reinforcing the ROS scavenging abilities of plants [34]. The exogenous foliar application of kinetin activates and stimulates the biosynthesis of secondary metabolites through the upregulation of the corresponding transcripts or by increasing the activities of the biosynthetic enzymes in a number of plants [37,39,40]. Therefore, due to the repressed enzyme activity during cold stress conditions, amplification of the nonenzymatic antioxidative system through kinetin application might offer a necessary tolerance mechanism to enhance the growth of plants, such as coffee.…”

The Potential Effects of Kinetin Implementation on Hybrid Rice Seed Production under Water Deficit

“…Based on the literature, varied concentrations of kinetin were applied to a variety of crops. Glycine betaine (100 mM) and kinetin (1 mM) in combination were applied to rice at the flowering stage as a foliar spray under water stress to enhance proline and soluble sugar concentrations in leaves [46]. Koprna et al [47] applied three cytokinin derivatives, with 10 µM concentration in field trial experiments by foliar spraying in winter wheat and spring barley at the tillering stage.…”

Influence of Glycine Betaine (Natural and Synthetic) on Growth, Metabolism and Yield Production of Drought-Stressed Maize (Zea mays L.) Plants

“…This enhancement in pigment concentrations may have been due to the role of GB in protecting the photosynthetic apparatus and stabilizing the structures of Rubisco and membranes in plants under water deficit conditions [37,38]. Moreover, it is known that GB improves the efficiency of photosynthetic machinery [38,39].…”