Title: Molecular Characterization and Plant Growth Promotion Potential of Endophytes from Thar Desert, Rajasthan India
The Great Indian Desert, also known as the Thar Desert, covers approximately 0.32 million km2 of the planet's surface, or 10% of India's whole geographic area. Despite being one of the smallest deserts in the world, it is home to a variety of habitats and species. One of the most challenging environments for plant growth is the desert ecosystem, where environmental challenges such water scarcity, extreme heat, salt, and irradiance limit plant diversity and dispersion. Due to its limited rainfall and high temperatures, Rajasthan's Thar Desert is one of the driest places on earth. Desert plants have developed a variety of stress tolerance techniques to get through their entire life cycle. Endophytes are defined as symbiotic bacterial and fungal communities that are found in intercellular and intracellular spaces of plants such as stem, root, leaves etc. and do not cause any negative impact on plant. The present research based on the sample collection from Thar desert of Rajasthan including Bikaner, Jaisalmer, Churu and Barmer districts of Rajasthan. The plants Leptadenia pyrotechnica, and Balanites aegyptiaca, were used for isolation of bacterial and fungal endophytes. Various bacterial and fungal species named Bacillus sp., Enterobacter sp., Pseudomonas sp., Sphingomonas sp., Aspergillus sp., Penicillium sp., Chaetomium sp., Trichoderma sp., Alternaria sp., Fusarium sp., Nigrospora sp., were isolated from these plants. Further these isolates were screened for their Plant Growth Promotion Activities such as nitrogen fixation, phosphate solubilization, HCN production, synthesis of siderophore, 1-aminocyclopropane-1-carboxylate (ACC) deaminase and extracellular enzyme production (amylase, chitinase, cellulase, protease, and catalase). These features of endophytic bacteria and fungi that encourage plant growth increase root length and density, which increases plant resistance to drought. Additionally, plant-endophytic bacteria help plants resist drought stress by creating a variety of volatile chemicals, indole-3-acetic acid, abscisic acid, and other drought-tolerant molecules. Indirectly, endophytic bacteria help inoculated plants' osmotic adjustment, relative water content, and antioxidant activity. The combined effects of this bacterial-mediated drought resistance and plant growth promotion mechanisms result in improved plant growth promotion and yield even under extreme drought circumstances.