Programmed Cell Death as a Response to High Light, UV and Drought Stress in Plants - Abiotic Stress: Plant Responses and Applications in Agriculture - page 230

The elucidation of mechanisms controlling drought stress responses has enabled to engineer
plants by the expression of specific stress-related genes. Although it was believed that the
modulation of osmoregulatory genes would be the best strategy, attempts failed to result in
any significant drought-stress tolerance improvement [203]. However, constitutive expres‐
sion of some LEA proteins has conferred tolerance to soil water deficit in transgenic rice
[204] and wheat [205]. Moreover, tomato plants overexpressing Arabidopsis CBF1 (DREB1B)
have exhibited improved drought tolerance [206]. Similar results have been obtained for
transgenic Arabidopsis and rice plants overexpressing stress-responsive NAC genes [207].
7. Conclusions
Plants have evolved various strategies to acclimate to different environmental stresses. The
most fundamental strategy is the development of high plasticity of plant tissues. It has been
demonstrated that programmed cell death plays an important role in this plasticity and sub‐
sequent adaptation to unfavorable conditions. There is a growing evidence that PCD is a
crucial process in both morphogenetic changes execution and the following adaptation. Al‐
though each decade brings a vast number of research, our understanding of plant PCD and
its underlying mechanisms is still in its early stage. Further insight into details of the PCD
molecular machinery in plants is important, since it is an attractive target for improving
stress tolerance and plant yield under adverse conditions. Essentially, it could lead to the
generation of pathogen-resistant and stress-tolerant crops as well as fruit varieties with an
extended shelf life.
Acknowledgments
This work was supported by the Welcome/2008/1 Program operated within the framework
of the Foundation for Polish Science, co-financed by the European Regional Development
Fund.
Abbreviations
ABA - abscisic acid; AOX - alternative oxidase; APX - ascorbate peroxidase; AsA - ascorbic
acid; BI - Bax-Inhibitor; CAT - catalase; Chl - chlorophyll; DBMIB - 2,5-dibromo-3-methyl-6-
isopropyl-p-benzoquinone; DCMU - 3,4-dichlorophenyl-1,1-dimethylurea; DHA - dehy‐
droascorbate; DHAR - dehydroascorbate reductase; EEE - excess excitation energy; EL -
excess light; ER - endoplasmic reticulum; ET - ethylene; ETC - electron transport chain; FAD
- flavin adenine dinucleotide; GA - gibberellic acid; GPX - glutathione peroxidase; GR - glu‐
tathione reductase; GSH - reduced glutathione; GSSG - oxidized glutathione; GST - gluta‐
thione-S- transferase; HL - high light; IAP - inhibitor of apoptosis; JA - jasmonic acid; HR -