preprints.org > biology and life sciences > agricultural science and agronomy > doi: 10.20944/preprints202401.0881.v1

Preprint Article Version 1 Preserved in Portico This version is not peer-reviewed

Version 1 : Received: 10 January 2024 / Approved: 11 January 2024 / Online: 11 January 2024 (07:26:48 CET)

Stresses due to drought and high soil salt content are the most severe threats to global rice pro-duction, causing a significant decline in rice yield. Therefore, this study examined the effects of treatment with various plant extracts on the stresses on rice plants associated with drought and high salinity. Additionally, this study examined various physiological and biochemical parameters such as growth, photosynthetic activity, chlorophyll content, and lipid peroxidation in rice plants after treatment with selected plant extracts under drought and salt stress conditions. Out of the eleven extracts tested, four extracts, namely soybean leaf, soybean stem, Chinese chive, and onion extracts, were found to effectively reduce drought stress. A reduction of only 24-37% in shoot fresh weight was observed in rice plants under drought stress that were treated with these ex-tracts compared to the 78% reduction observed in control plants. In addition, rice plants under salt stress which were treated with soybean leaf, soybean stem, moringa (Moringa oleifera), and Undaria pinnatifida extracts were observed to have lower reductions in shoot fresh weight (3-23%) com-pared to the control plants (43%). The effectiveness varied with the concentrations of the plant ex-tracts. Water content was higher in the rice plants treated with extracts than in the control plants after 6 days of drought and salt stress, but not after 4 days of drought and salt stress. Although photosynthetic efficiency (Fv/Fm) and electron transport rate (ETR), and the content of pigments (chlorophyll and carotenoid) varied based on the types and levels of stress and the extracts that the rice plants were treated with, generally photosynthetic efficiency and pigment contents were higher in the treated rice compared to control plants than in the control plants. Reactive oxygen species (ROS) such as the superoxide radical, hydrogen peroxide (H2O2), and malondialdehyde (MDA) levels increased as the duration of the period of stress increased. ROS and MDA levels were lower in the treated rice compared to control plants. Proline and soluble sugar accumulation also increased as the duration of the stressperiod increased. However, proline and soluble sugar ac-cumulation were lower in the treated rice compared to control plants. Generally, all the parame-ters investigated in this study were similar regardless of the plant extract used for treating the rice plants. Thus, extracts found to be effective in this study can be used to alleviate the adverse effects of stress on rice crops associated with drought and high salinity soil.

biostimulant; drought stress; plant extract; rice; salt stress

Biology and Life Sciences, Agricultural Science and Agronomy

* All users must log in before leaving a comment