tailieunhanh - Cell Metabolism Cell Homeostasis and Stress Response Part 3

Tham khảo tài liệu 'cell metabolism cell homeostasis and stress response part 3', khoa học tự nhiên, công nghệ sinh học phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Regulation of Gene Expression in Response to Abiotic Stress in Plants 21 Sachs 1996 found that gene induction in regions of primary root and mesocotyl exhibiting signs of development of aerenchyma in flooded soil suggesting an association between this enzyme and the structural changes induced by this type of stress. The plants survive under conditions of anoxia replacing the aerobic metabolism by anaerobic Drew 1997 . However before the metabolic adjustments are made the stress can be perceived and signaled to induce the appropriate cellular and molecular responses Dat et al. 2004 . Studies on plants under conditions of O2 deficiency in the soil have focused the role of calcium Ca2 as a marker Subbaiah et al. 1998 Subbaiah et al. 2000 . Molecular processes are modulated by Ca2 via high-affinity proteins such as calmodulin CaM and its isoforms in plants Zielinski 1998 . The complex active Ca2 -CaM can regulate the activity of many target molecules associated with plant responses to stress Snedden Fromm 2001 . Many CaM have been identified in herbaceous plants but for woody plants have been little information. Folzer et al. 2005 were the first to identify a family of CaM in woody plant Quercus petraco Liebl. demonstrating that the isolated isoforms exhibit organ-specific distribution and differential expression in the plant when the plant is subjected to flooding of the soil suggesting that each isoform plays a role and specific activation or modulation of target enzymes directly associated with the stress response Subbaiah et al. 2000 . Changes in gene expression in plants induced by lack of O2 in the soil levels occur in transcriptional translational and post-translational Sachs et al. 1980 . These changes result in immediate suppression of protein synthesis pre-existing with simultaneous selective synthesis of transition of polypeptides TPs 33 kDa and after prolonged exposure to this condition of the plant selective synthesis of anaerobic proteins ANPs Sachs et .