Auxin: An emerging regulator of tuber and storage root development.

Many tuber and storage root crops owing to their high nutritional values offer high potential to overcome food security issues. The lack of information regarding molecular mechanisms that govern belowground storage organ development (except a tuber crop, potato) has limited the application of biotechnological strategies for improving storage crop yield. Phytohormones like gibberellin and cytokinin are known to play a crucial role in governing potato tuber development. Another phytohormone, auxin has been shown to induce tuber initiation and growth, and its crosstalk with gibberellin and strigolactone in a belowground modified stem (stolon) contributes to the overall potato tuber yield. In this review, we describe the crucial role of auxin biology in development of potato tubers. Considering the emerging reports from commercially important storage root crops (sweet potato, cassava, carrot, sugar beet and radish), we propose the function of auxin and related gene regulatory network in storage root development. The pattern of auxin content of stolon during various stages of potato tuber formation appears to be consistent with its level in various developmental stages of storage roots. We have also put-forward the potential of three-way interaction between auxin, strigolactone and mycorrhizal fungi in tuber and storage root development. Overall, we propose that auxin gene regulatory network and its crosstalk with other phytohormones in stolons/roots could govern belowground tuber and storage root development.

Stress and Stressors among Medical Undergraduate Students: A Cross-sectional Study in a Private Medical College in Tamil Nadu.

BACKGROUND: Medical education is perceived as being stressful, and a high level of stress may have a negative effect on cognitive functioning and learning of students in a medical school. OBJECTIVES: To (a) assess the perceived stress among medical undergraduate students, (b) identify the sources of stress, and (c) find an association of perceived stress with sociodemographic characteristics and various stressors. MATERIALS AND METHODS: A cross-sectional study was conducted among medical undergraduate students in a private medical college in Tamil Nadu. A total of 750 medical students from 1st year to final year were invited to participate in the study. Self-administered questionnaire was used to collect data regarding sociodemographic profile, perceived stress using perceived stress scale-14 and academic, psychosocial and environmental stressors. Descriptive statistics was used to describe the sociodemographic characteristics, sources of stress and perceived stress. Logistic regression analyses were carried out to assess determinants of stress. RESULTS: The overall response rate was 93.33% (700 out of 750 students). The mean perceived stress score was 25.64 ± 5.44. Higher age-group, year of studying bachelor of medicine and bachelor of surgery, vastness of academic curriculum, fear of poor performance in examination, lack of recreation, loneliness, family problem, and accommodation away from home were important determinants of perceived stress. CONCLUSIONS: The perceived stress was higher among higher age group and final year medical students. Academic, psychosocial, and environmental stressors are associated with perceived stress. Reframing the academic curriculum and examination patterns, incorporating recreational and sports activities, and establishment of counseling cells in the institution is needed.