Pests are major factor affecting the crop yield, quality, and esthetic value. Although pest resistance is genetically controlled, it is mediated through physiological and biochemical processes interrelated with the nutritional status of the plant. Nutrition of plant may determine its resistance or susceptibility to pests. An experiment was conducted to determine whether and up to what extent varying concentrations of N modulate the infesting rate of whitefly on Okra (Hibiscus esculentus). Twenty-one-dayold okra plants were subjected to five concentrations of 4, 8, 12, 16, and 20 mM N for 30 days. Number of eggs, nymph were counted on each plant after every 4 days. Growth and yield of okra plants increased with increasing supply of N but it decreased slightly at the highest level of N (20 mM). Leaf soluble proteins, amino acids, and soluble sugars were determined on fresh weight basis. From these results, it is clear that increasing N level increased the biosynthesis or accumulation of protein, free amino acid, and sugars that might have attracted more whitefly for feeding.
Drought is one of the most important abiotic stress factors limiting maize production worldwide. The objective of this study was to investigate whether photoprotection of PSII was associated with the degree of drought tolerance and yield in three maize hybrids (30Y87, 31R88, P3939). To do this, three maize hybrids were subjected to three cycles of drought, and we measured the activities of photosystem II (PSII) and photosystem I (PSI). In a second field experiment, three maize hybrids were subjected to drought by withholding irrigation, and plant water status, yield and yield attributes were measured. Drought stress decreased leaf water potential (ΨL) in three maize hybrids, and this reduction was more pronounced in hybrid P3939 (−40%) compared to that of 30Y87 (−30%). Yield and yield attributes of three maize hybrids were adversely affected by drought. The number of kernels and 100-kernel weight was the highest in maize hybrid 30Y87 (−56%, −6%), whereas these were lowest in hybrid P3939 (−88%, −23%). Drought stress reduced the quantum yield of PSII [Y(II)], photochemical quenching (qP), electron transport rate through PSII [ETR(II)] and NPQ, except in P3939. Among the components of NPQ, drought increased the Y(NPQ) with concomitant decrease in Y(NO) only in P3939, whereas Y(NO) increased in drought-stressed plants of hybrid 30Y87 and 31R88. However, an increase in cyclic electron flow (CEF) around PSI and Y(NPQ) in P3939 might have protected the photosynthetic machinery but it did not translate in yield. However, drought-stressed plants of 30Y87 might have sufficiently downregulated PSII to match the energy consumption in downstream biochemical processes. Thus, changes in PSII and PSI activity and development of NPQ through CEF are physiological mechanisms to protect the photosynthetic apparatus, but an appropriate balance between these physiological processes is required, without which plant productivity may decline.
Drought is one of the major environmental stresses that produces adverse effects on plants.Vast areas of agricultural land is susceptible to drought. Drought induced yield loss of crops has negative effects on the economy of a country. Among phytohormones, Abscisic Acid (ABA) induces abiotic stress tolerance in plants, and directs a complex regulatory network involving multiple transporters, up-regulation of ABA biosynthesis genes and various signalling pathways that enable plants to withstand low water availability. The current study was designed to understand ABA synthesis, its transport across the plant during stress and its mechanism to induce stomatal closure by using different in silico tools, because the complete ABA mediated drought tolerance has not yet been reported. In the current study, seven transporters, four ABA biosynthesis enzymes, deconjugation enzyme and a core complex of ABA signalling was verified through Modeller 9.10 and Molecular Operating Environment
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.