Plants often face incompatible growing environments like drought, salinity, cold, frost, and elevated temperatures that affect plant growth and development leading to low yield and, in worse circumstances, plant death. The arsenal of versatile compounds for plant consumption and structure is called metabolites, which allows them to develop strategies to stop enemies, fight pathogens, replace their competitors and go beyond environmental restraints. These elements are formed under particular abiotic stresses like flooding, heat, drought, cold, etc., and biotic stress such as a pathogenic attack, thus associated with survival strategy of plants. Stress responses of plants are vigorous and include multifaceted crosstalk between different levels of regulation, including regulation of metabolism and expression of genes for morphological and physiological adaptation. To date, many of these compounds and their biosynthetic pathways have been found in the plant kingdom. Metabolites like amino acids, phenolics, hormones, polyamines, compatible solutes, antioxidants, pathogen related proteins (PR proteins), etc. are crucial for growth, stress tolerance, and plant defense. This review focuses on promising metabolites involved in stress tolerance under severe conditions and events signaling the mediation of stress-induced metabolic changes are presented.

Rice (Oryza sativa L.) is an important crop that is grown worldwide to supply the world’s expanding food demand. In the current study, the effects of plant growth-promoting rhizobacteria (PGPR) and Arbuscular mycorrhizal fungi (AMF) on soil fertility and rice growth were explored. Rice plants were inoculated to evaluate how AMF fungi and PGPR affect various aspects of soil and plants, implicating abiotic stress tolerances. The experiment was carried out in a completely randomized design with three replicates under the controlled conditions. Results depicted that the plants that were inoculated with a mixture of AMF and PGPR had better yields and nutritional concentrations, while both AMF and PGPR lowered soil pH and organic matter differently. Similarly, AMF and PGPR treatments significantly increased the amount of N, P, K, and B in the post-harvest soil. The PGPR-inoculated plants had a 10–40% higher buildup of N in their tissues. Similarly, when they were compared with non-infected plants, AMF-inoculated treatments demonstrated a greater N accumulation in the rice tissue. The maximum P content in plant tissues was 0.149% in PGPR5-infected plants, either alone or in combination with AMF. In T12, AMF + PGPR5 inoculated rice plants, the maximum K uptake was 1.98%, which was 54% higher than the control treatment. The sole application of AMF raised K buildup in rice tissues by 38% compared with the control treatment. The improved productivity of plants with AMF and PGPR (especially with PGPR5) was attributed to the increased availability of nutrients in the soil. As a result, rice plant growth, yield, and essential element uptakes were boosted significantly. The present study’s results suggested using the combined application of AMF + PGPR5 for improving the rice yield and for sustaining the soil health.

Damping-off disease in chili (Capsicum annum L.) cultivation is a significant global issue, severely affecting seeds, seedlings, and young plants, regardless of the location of cultivation, whether in greenhouses or open fields. Despite chili being a widely popular vegetable used in various cuisines globally, farmers face challenges in meeting the growing demand due to the extensive damage caused by this disease, ranging from 20 to 85%. The shelf life and quality of mature pods are also severely affected. Damping-off disease is mainly caused by soil-borne fungus from the Pythium species, with additional contributions from Phytophthora, Fusarium, and Rhizoctonia species. These pathogens’ adaptability to diverse environmental conditions and resistance to synthetic fungicides make controlling damping-off on a commercial scale challenging. However, integrated disease management has shown promising results as a remedial approach. In this review, we discuss the current state of chili diseases, the nature of the pathogens causing damping-off, the epidemiology of the disease, and various control mechanisms. In this review, we broadly discuss the current state of chili diseases, the nature of the pathogens causing damping-off, the epidemiology of the disease, and various control mechanisms. Furthermore, we highlight the importance and efficacy of integrated disease management techniques, along with future prospects in unexplored areas, such as host–pathogen interaction and sustainable disease control measures. The information in this review aims to assist chili growers in understanding the epidemiology and management of damping-off in chili cultivation.

Corrigendum: Role of Promising Secondary Metabolites to Confer Resistance Against Environmental Stresses in Crop Plants: Current Scenario and Future Perspectives

Insect-vectored plant viruses pose a serious threat to sustainable production of economically important crops worldwide. This demands a continuous search for environmentally-friendly, sustainable and efficient approaches based on biological agents to address the mounting challenges of viral disease management. To date, the efficacy of actinomycetes bacteria against DNA plant viruses remains unknown. Here, through comparative analyses, we demonstrate that the RFS-23 strain of Streptomyces cellulase possesses protective activity as it positively regulated the plant growth and development. and diminished the severity, of disease symptoms, together with reduced accumulation of Tomato yellow leaf curl virus (TYLCV) DNA. The RFS-23 strain maintained relative chlorophyll contents by promoting the expression of genes (CLH1, HEMA1 and PORA) associated with chlorophyll biogenesis. As compared to another strain, CTF-20, the RSF-23 induced a significantly higher expression of plant defense-related genes (NbCIS and NbNCED) associated with biogenesis and accumulation of salicylic acid and abscisic acid. Additionally, the activity of antioxidant enzymes (SOD, CAT, POD and MDA) was significantly enhanced by RSF-23 treatment, despite the presence of viral infection. These findings suggest that RSF-23 is a novel biocontrol agent with protective activity, and it could be a potential candidate for the management of plant viral infections.

Tilletia laevis causes common bunt disease in wheat, with severe losses of production yield and seed quality. Metabolomics studies provide detailed information about the biochemical changes at the cell and tissue level of the plants. Ultrahigh-performance liquid chromatography–Q-exactive mass spectrometry (UPLC-QE-MS) was used to examine the changes in wheat grains after T. laevis infection. PCA analysis suggested that T. laevis-infected and non-infected samples were scattered separately during the interaction. In total, 224 organic acids and their derivatives, 170 organoheterocyclic compounds, 128 lipids and lipid-like molecules, 85 organic nitrogen compounds, 64 benzenoids, 31 phenylpropanoids and polyketides, 21 nucleosides, nucleotides, their analogues, and 10 alkaloids and derivatives were altered in hyphal-infected grains. According to The Kyoto Encyclopedia of Genes and genomes analysis, the protein digestion and absorption, biosynthesis of amino acids, arginine and proline metabolism, vitamin digestion and absorption, and glycine, serine, and threonine metabolism pathways were activated in wheat crops after T. laevis infection.