In-silico analysis and transformation of OsMYB48 transcription factor driven by CaMV35S promoter in model plant - Nicotiana tabacum L. conferring abiotic stress tolerance.

Global crop yield has been affected by a number of abiotic stresses. Heat, salinity, and drought stress are at the top of the list as serious environmental growth-limiting factors. To enhance crop productivity, molecular approaches have been used to determine the key regulators affecting stress-related phenomena. MYB transcription factors (TF) have been reported as one of the promising defensive proteins against the unfavorable conditions that plants must face. Different roles of MYB TFs have been suggested such as regulation of cellular growth and differentiation, hormonal signaling, mediating abiotic stress responses, etc. To gain significant insights, a comprehensive in-silico analysis of OsMYB TF was carried out in comparison with 21 dicot MYB TFs and 10 monocot MYB TFs. Their chromosomal location, gene structure, protein domain, and motifs were analyzed. The phylogenetic relationship was also studied, which resulted in the classification of proteins into four basic groups: groups A, B, C, and D. The protein motif analysis identified several conserved sequences responsible for cellular activities. The gene structure analysis suggested that proteins that were present in the same class, showed similar intron-exon structures. Promoter analysis revealed major cis-acting elements that were found to be responsible for hormonal signaling and initiating a response to abiotic stress and light-induced mechanisms. The transformation of OsMYB TF into tobacco was carried out using the Agrobacterium-mediated transformation method, to further analyze the expression level of a gene in different plant parts, under stress conditions. To summarize, the current studies shed light on the evolution and role of OsMYB TF in plants. Future investigations should focus on elucidating the functional roles of MYB transcription factors in abiotic stress tolerance through targeted genetic modification and CRISPR/Cas9-mediated genome editing. The application of omics approaches and systems biology will be indispensable in delineating the regulatory networks orchestrated by MYB TFs, facilitating the development of crop genotypes with enhanced resilience to environmental stressors. Rigorous field validation of these genetically engineered or edited crops is imperative to ascertain their utility in promoting sustainable agricultural practices.

Molecular mechanisms of plant tolerance to heat stress: current landscape and future perspectives.

KEY MESSAGE: We summarize recent studies focusing on the molecular basis of plant heat stress response (HSR), how HSR leads to thermotolerance, and promote plant adaptation to recurring heat stress events. The global crop productivity is facing unprecedented threats due to climate change as high temperature negatively influences plant growth and metabolism. Owing to their sessile nature, plants have developed complex signaling networks which enable them to perceive changes in ambient temperature. This in turn activates a suite of molecular changes that promote plant survival and reproduction under adverse conditions. Deciphering these mechanisms is an important task, as this could facilitate development of molecular markers, which could be ultimately used to breed thermotolerant crop cultivars. In current article, we summarize mechanisms involve in plant heat stress acclimation with special emphasis on advances related to heat stress perception, heat-induced signaling, heat stress-responsive gene expression and thermomemory that promote plant adaptation to short- and long-term-recurring heat-stress events. In the end, we will discuss impact of emerging technologies that could facilitate the development of heat stress-tolerant crop cultivars.

Out of the Blue: A Case of Blue Subungual Discoloration Associated with Prolonged Tetracycline Use.

Tetracycline derivatives are antibiotics such as minocycline and doxycycline that have been commonly utilized for inflammatory dermatological conditions such as acne and rosacea. Hyperpigmentation of the skin, nails, thyroid, oral mucosa, teeth, and bones is a known but rare side effect of prolonged tetracycline use. The hyperpigmentation typically takes months to years to develop. There may also be residual changes to the skin after discontinuation of the medication. For this reason, the time tetracyclines are used should be minimized and patients should be monitored for the skin findings. Subungual discoloration carries a broad differential including infectious, inflammatory, metabolic, malignant or systemic diseases. Knowledge of this side effect is crucial in order to avoid unnecessary testing in determining the etiology of the subungual discoloration. We report on a case of a patient who has been on long-term minocycline use for adult acne management. He was initially on minocycline for six years, but due to minocycline-induced hyperpigmentation of his ears and fingernails, he had switched to doxycycline. One year later, the skin hyperpigmentation of the ears regressed; however, the blue subungual hyperpigmentation of his hands progressively become more prominent without any other significant symptoms.