RESUMO
BACKGROUND: Pongamia is considered an important biofuel species worldwide. Drought stress in the early growth stages of Pongamia influences negatively on the germination and seedling development. Due to lack of cultivar stability under drought stress conditions, establishment of successful plantation in drought hit areas becomes a major problem. To address this issue, drought stress response of four Pongamia genotypes was studied at morphological, physio-chemical and transcriptome levels. METHODS AND RESULTS: Drought stress was levied by limiting water for 15 days on three months old seedlings of four genotypes. A significant effect of water stress was observed on the traits considered. The genotype NRCP25 exhibited superior morpho-physiological, biochemical drought responses. Also, the genotype had higher root length, photosynthetic pigments, higher antioxidant enzymes and solute accumulation compared to other genotypes. In addition, transcript profiling of selected drought responsive candidate genes such as trehalose phosphate synthase 1 (TPS1), abscisic acid responsive elements-binding protein 2 (ABF2-2), heat shock protein 17 (HSP 17 kDa), tonoplast intrinsic protein 1 (TIP 1-2), zinc finger homeodomain protein 2 (ZFP 2), and xyloglucan endotransglucolase 13 (XET 13) showed only up-regulation in NRCP25. Further, the transcriptome responses are in line with key physio-chemical responses exhibited by NRCP25 for drought tolerance. CONCLUSIONS: As of now, there are no systematic studies on Pongamia drought stress tolerance; therefore this study offers a comprehensive understanding of whole plant drought stress responsiveness of Pongamia. Moreover, the results support important putative trait indices with potential candidate genes for drought tolerance improvement of Pongamia.
Assuntos
Secas , Millettia , Ácido Abscísico , Antioxidantes/metabolismo , Biocombustíveis , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/genética , Proteínas de Choque Térmico/genética , Proteínas de Homeodomínio/genética , Millettia/genética , Millettia/metabolismo , Fosfatos , Estresse Fisiológico/genética , Transcriptoma/genética , TrealoseRESUMO
The purpose of this study was to contribute to the nascent literature on resilience and suicidality among Black Americans by examining factors that may predict less suicidal behavior among this population. The authors hypothesized that reasons for living, life satisfaction, and religious awareness would account for unique variance in suicidal thoughts and behavior among Black Americans, above the variance accounted for by depressive symptoms. They also hypothesized that reasons for living and religious awareness would be stronger inverse predictors among Black women than Black men. Results indicated that both depression and life satisfaction were stronger predictors of suicidal behavior among Black men. Among women, only reasons for living was a significant inverse predictor of suicidal thoughts and behavior. More frequent reasons for living moderated the relationship between depression and suicidal thoughts and behavior among Black women.
