Induction of Tolerance in Groundnut Plants Against Drought Stress and Cercospora Leaf Spot Disease with Exogenous Application of Arginine and Sodium Nitroprusside Under Field Conditions

Abstract

Naturally, under field conditions, plants are regularly experienced by a mixture of two or more stress factors. Drought is a major abiotic stress, and fungal pathogens characterize a main biotic stress challenge faced by plants and impact negatively on plant development and productivity. We propose that foliar application of nitric oxide (NO) donors can have positive effects on the induction of tolerance to biotic and abiotic stress on groundnut plants. This investigation was carried out to study the changes in growth, some biochemical aspects, and yield and quality of groundnut plants as well as induction of resistance to Cercospora leaf spot disease in response to nitric oxide (NO) donors, sodium nitroprusside (SNP), and arginine (Arg) (2.5, 5.0, and 7.5 mM) under two water irrigation levels 100% and 75% of water irrigation requirements (WIR), in two field experiments through two successive growing seasons of 2021 and 2022. Decreasing irrigation water significantly reduced shoot length, branches numberplant-1, shoot fresh and dry weight, photosynthetic pigments components, endogenous indole acetic acid (IAA) contents, and yield components. Furthermore, root fresh and dry weight, phenols, total soluble sugars (TSS), proline contents, and the accumulation of hydrogen peroxide (H2O2) and lipid peroxidation of groundnut leaves increased significantly. Contrarily, foliar application with Arg and SNP alleviated the negative influences of drought on growth and productivity of groundnut plants via enhancing photosynthetic pigments, IAA, phenolic compounds, TSS, and proline contents. Additionally, SNP and Arg significantly decreased oxidative damage through decreasing H2O2 and lipid peroxidation by the induction of antioxidant enzymes. Remarkably, the increase of drought level led to a reduction in Cercospora leaf spot (CLS) disease with the use of high concentrations of both Arg and SNP. Interestingly, in both stressed and unstressed plants, SNP treatment at 7.5 mM was the most effective in reducing the incidence and severity of disease, while Arg at 2.5 mM recorded the lowest reduction compared to other treatments. In conclusion, foliar treatment of either SNP or Arg is a profound effect on modulating the drought stress and induction of resistance to Cercospora leaf spot disease of groundnut plants throughout regulating physiological and biochemical processes associated with photosynthesis and oxidative responses.

Selenium Improves the Control Efficacy of Phytophthora nicotianae by Damaging the Cell Membrane System and Promoting Plant Energy Metabolism

“…Disease resistance-signaling molecules such as jasmonate, salicylic acid (SA), and abscisic acid (ABA) are induced during pathogen infestation, with all these pathways playing crucial roles in regulating plant resistance to pathogens. 14,15 Studies have reported that β-aminobutyric acid enhances tobacco resistance to P. nicotianae by increasing SA content and decreasing ABA content. 16 Primary and secondary metabolites in plants, including amino acids, carbohydrates, lipids, and organic acids, undergo alterations to regulate cellular metabolism and maintain homeostasis under biological stress.…”

“…In the context of plant–pathogen interactions, enzymatic activity and hormonal signaling are pivotal for plant resistance. Disease resistance-signaling molecules such as jasmonate, salicylic acid (SA), and abscisic acid (ABA) are induced during pathogen infestation, with all these pathways playing crucial roles in regulating plant resistance to pathogens. , Studies have reported that β-aminobutyric acid enhances tobacco resistance to P. nicotianae by increasing SA content and decreasing ABA content .…”

Effect of Abiotic Signals on the Accumulation of Saponarin in Barley Leaves in Hydroponics Under Artificial Lights

“…The wavelength of photosynthetically active radiation (PAR) can be divided into long and short wavelength groups; a long wavelength, such as red color and near IR, is essentially used for photosynthesis in chlorophyll, and a short wavelength of PAR, such as blue and UV lights, involves ROS signal generation. ,− Thus, the quantity balance of long and short wavelengths of PAR could control the photosynthesis rate and the carbon metabolite flow as well as ROS levels in plants, and these might increase the biosynthesis of flavonoidal antioxidants such as saponarin and lutonarin. At the same time, the excess ROS generation could damage cell components and suppress the growth of plants and the accumulation of antioxidative metabolites. − Recently, the effects of light quality and quantity on the growth and saponarin production in YBL were reported under light-emitting diode (LED) light; however, the accumulated saponarin concentrations and the biomass of YBL were lower than under sunlight conditions. ,− In the reports, the growth inhibition and phytotoxicity were shown over 400 μmol m –2 s –1 (PPFD) of a white LED light, even though it was significantly lower in light quantity than sunlight . To understand this, the light quality effect should be investigated on ROS generation, the photosynthesis rate, and the metabolites for saponarin.…”

“…At the same time, the excess ROS generation could damage cell components and suppress the growth of plants and the accumulation of antioxidative metabolites. 33 − 36 Recently, the effects of light quality and quantity on the growth and saponarin production in YBL were reported under light-emitting diode (LED) light; however, the accumulated saponarin concentrations and the biomass of YBL were lower than under sunlight conditions. 17 , 23 − 25 In the reports, the growth inhibition and phytotoxicity were shown over 400 μmol m –2 s –1 (PPFD) of a white LED light, even though it was significantly lower in light quantity than sunlight.…”

Supplemental Sodium Nitroprusside and Spermidine Regulate Water Balance and Chlorophyll Pigments to Improve Sunflower Yield under Terminal Drought

“…Currently, drought stress has become a major issue in agricultural production around the world. 69 As a more devastating stress factor, drought usually disrupts tissue water relations, nutrient absorption, and metabolic processes that makes the plants survival difficult to drought situations. 2 , 3 Drought also causes chlorosis and loss of cell turgidity, impairs net photosynthesis and root growth, assimilates translocation, imbalances membrane permeability, alters cell functions, and impairs enzyme activation and stomatal conductance, consequently reducing crop productivity.…”