Browsing by Author "Hossain, Md Motaher"
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Item Carrageenans as biostimulants and bio-elicitors: plant growth and defense responses(2024) Hossain, Md Motaher; Sultana, Farjana; Khan, Sabia; Nayeema, Jannatun; Mostafa, Mahabuba; Ferdus, Humayra; Tran, Lam Son Phan (TTU); Mostofa, Mohammad GolamIn the context of climate change, the need to ensure food security and safety has taken center stage. Chemical fertilizers and pesticides are traditionally used to achieve higher plant productivity and improved plant protection from biotic stresses. However, the widespread use of fertilizers and pesticides has led to significant risks to human health and the environment, which are further compounded by the emissions of greenhouse gases during fertilizer and pesticide production and application, contributing to global warming and climate change. The naturally occurring sulfated linear polysaccharides obtained from edible red seaweeds (Rhodophyta), carrageenans, could offer climate-friendly substitutes for these inputs due to their bi-functional activities. Carrageenans and their derivatives, known as oligo-carrageenans, facilitate plant growth through a multitude of metabolic courses, including chlorophyll metabolism, carbon fixation, photosynthesis, protein synthesis, secondary metabolite generation, and detoxification of reactive oxygen species. In parallel, these compounds suppress pathogens by their direct antimicrobial activities and/or improve plant resilience against pathogens by modulating biochemical changes via salicylate (SA) and/or jasmonate (JA) and ethylene (ET) signaling pathways, resulting in increased production of secondary metabolites, defense-related proteins, and antioxidants. The present review summarizes the usage of carrageenans for increasing plant development and defense responses to pathogenic challenges under climate change. In addition, the current state of knowledge regarding molecular mechanisms and metabolic alterations in plants during carrageenan-stimulated plant growth and plant disease defense responses has been discussed. This evaluation will highlight the potential use of these new biostimulants in increasing agricultural productivity under climate change.Item Ethanol Positively Modulates Photosynthetic Traits, Antioxidant Defense and Osmoprotectant Levels to Enhance Drought Acclimatization in Soybean(2022) Rahman, Md Mezanur (TTU); Mostofa, Mohammad Golam (TTU); Das, Ashim Kumar; Anik, Touhidur Rahman; Keya, Sanjida Sultana (TTU); Ahsan, S. M.; Khan, Md Arifur Rahman; Ahmed, Minhaz; Rahman, Md Abiar; Hossain, Md Motaher; Tran, Lam Son Phan (TTU)Drought is a major environmental threat to agricultural productivity and food security across the world. Therefore, addressing the detrimental effects of drought on vital crops like soybean has a significant impact on sustainable food production. Priming plants with organic compounds is now being considered as a promising technique for alleviating the negative effects of drought on plants. In the current study, we evaluated the protective functions of ethanol in enhancing soybean drought tolerance by examining the phenotype, growth attributes, and several physiological and biochemical mechanisms. Our results showed that foliar application of ethanol (20 mM) to drought-stressed soybean plants increased biomass, leaf area per trifoliate, gas exchange features, water-use-efficiency, photosynthetic pigment contents, and leaf relative water content, all of which contributed to the improved growth performance of soybean under drought circumstances. Drought stress, on the other hand, caused significant accumulation of reactive oxygen species (ROS), such as superoxide and hydrogen peroxide, and malondialdehyde, as well as an increase of electrolyte leakage in the leaves, underpinning the evidence of oxidative stress and membrane damage in soybean plants. By comparison, exogenous ethanol reduced the ROS-induced oxidative burden by boosting the activities of antioxidant enzymes, including peroxidase, catalase, glutathione S-transferase, and ascorbate peroxidase, and the content of total flavonoids in soybean leaves exposed to drought stress. Additionally, ethanol supplementation increased the contents of total soluble sugars and free amino acids in the leaves of drought-exposed plants, implying that ethanol likely employed these compounds for osmotic adjustment in soybean under water-shortage conditions. Together, our findings shed light on the ethanol-mediated protective mechanisms by which soybean plants coordinated different morphophysiological and biochemical responses in order to increase their drought tolerance.Item Sclerotinia sclerotiorum (Lib.) de Bary: Insights into the Pathogenomic Features of a Global Pathogen(2023) Hossain, Md Motaher; Sultana, Farjana; Li, Weiqiang; Tran, Lam Son Phan (TTU); Mostofa, Mohammad GolamSclerotinia sclerotiorum (Lib.) de Bary is a broad host-range fungus that infects an inclusive array of plant species and afflicts significant yield losses globally. Despite being a notorious pathogen, it has an uncomplicated life cycle consisting of either basal infection from myceliogenically germinated sclerotia or aerial infection from ascospores of carpogenically germinated sclerotia. This fungus is unique among necrotrophic pathogens in that it inevitably colonizes aging tissues to initiate an infection, where a saprophytic stage follows the pathogenic phase. The release of cell wall-degrading enzymes, oxalic acid, and effector proteins are considered critical virulence factors necessary for the effective pathogenesis of S. sclerotiorum. Nevertheless, the molecular basis of S. sclerotiorum pathogenesis is still imprecise and remains a topic of continuing research. Previous comprehensive sequencing of the S. sclerotiorum genome has revealed new insights into its genome organization and provided a deeper comprehension of the sophisticated processes involved in its growth, development, and virulence. This review focuses on the genetic and genomic aspects of fungal biology and molecular pathogenicity to summarize current knowledge of the processes utilized by S. sclerotiorum to parasitize its hosts. Understanding the molecular mechanisms regulating the infection process of S. sclerotiorum will contribute to devising strategies for preventing infections caused by this destructive pathogen.