Adebanjo, O. A. | Search bioRxiv

bioRxiv2022

The Physiological Response of Salt and Drought-Stressed Plant to Exogenous Application of Salicylic Acid

Salinity and osmotic stress affect crop growth and yield. To meet the food demand of the increasing global population, there is a need to continually study the plant-stress factor relationship. This experiment studies the physiological response of salt and drought-stressed plant to exogenous application of salicylic acid. Tomato plants were grown in medium, under controlled conditions. The six treatments (T1 - control, T2 - MgSO4 for salinity stress, T3 - 5% PEG 8000 for osmotic stress, T4 - control + salicylic acid, T5 - MgSO4 + salicylic acid, T6 - 5% PEG 8000 + salicylic acid) were replicated six times to make a total of 36 plants. The treatments were assessed for parameters associated with photosynthetic parameters and yield: chlorophyll content, net photosynthetic rate, leaf water potential, fresh arial weight, leaf ion content, intercellular carbon dioxide concentration, transpiration rate and gaseous exchange. The result showed that the exogenous application of salicylic acid increased the leaf water potential of both the stressed and non-stressed plants. However, for other parameters, the role of MgSO4 and %PEG in inducing salinity stress and drought stress. Respectively, was not clearly observed. Likewise, the exogenous application of salicylic acid showed no clear effect in stressed plants, relative to unstressed plants. Hence, the observations from this experiment showed a high variation in physiological responses and a repeat of the experiment can be considered to further investigate the validation of the role of salicylic acid in plants under salt and osmotic stress conditions.

plant biology↗

bioRxiv2022

Water Stress Effect on the Growth of Lactuca sativa and Araujia sericifera

Water is the medium through which nutrients are transported from the soil into plants systems. Without soil water, the growth and yield of plants are negatively affected. This experiment compares the effect of water stress on the biomass production and chlorophyll content of lettuce (Lactuca sativa) and a weed species - moth plant (Araujia sericifera). The seedlings of the two plant species each were given three irrigation levels: 100% (T1), 50% (T2) and 0% (T3) field capacity of the growth medium - a mixture of peat moss (SuliFlor SF1(R)) and perlite (Perlindustria(R)) at ratio (3:1). The treatments for each plant were replicated five times, and the treatment lasted six weeks. Data were collected on moisture content and salinity of growing media, fresh and dry weight of shoot and root of plants, height, number of leaves, leaf area and chlorophyll content of leaf. The result showed that the water stress conditions have no significant effect on the chlorophyll, plant height and number of leaves of the two plant species. While the moth plant was not significantly affected by the stress conditions, lettuce recorded a significant reduction in leaf area, and in the dry weight of root and aerial part of the totally stressed plants, this shows that lettuce growth is significantly affected by water stress. Hence, moth plant tolerates water stress conditions more than the lettuce plant and this result may also be indicative of the survival of the moth plant if it infests a lettuce field.

plant biology↗