Agriculture Reference
In-Depth Information
11 Future Perspectives
Plants, as other living beings, are continuously exposed to a wide range of abiotic
stresses and, due to their sessile lifestyle, they have evolved highly sensitive stress
responses. Abiotic stresses are critical constraints to crop productivity which has to
maintain stable yields, associated with good quality and high nutritional value in order
to address the increasing food demand. Drought, salinity, and land desertification are
increasing on a global scale together with enormous economical losses. The impact of
genotoxic stress, resulting from adverse environmental conditions, on the plant defense
machinery represents a key issue, which has not been investigated properly so far.
Studies on the effects of genotoxic stress on the global gene expression have
been carried out in the model plant
Arabidopsis
, highlighting the involvement of
different gene categories, e.g., defense-related, DNA-repair, cell cycle-regulating
and signal-transduction genes. Some of these functions, particularly those related
to the plant antioxidant response, have been deeply investigated taking advantage
of genetically modified systems designed for the overexpression and/or silencing
of the target genes. In other cases, the defective mutants turned out to be a valuable
tool in eliciting more information.
The role of DNA repair genes as essential components of the plant response to
genotoxic stress has been recognized, but the direct link between these specific
functions and the protective mechanisms activated under adverse environmental
conditions, needs to be better defined. There is general awareness that the study of
DNA repair genes might be informative for the genetic improvement of crops and
for the design of new plant breeding strategies.
The physiology of DNA repair deserves more attention at the level of stress
perception, by defining the molecular determinants (receptors, signal molecules,
transcription regulators). The current knowledge on DNA repair pathways should
be expanded, assessing the roles played in plants by newly identified genes. The
functional characterization of DNA repair genes by transgenic approaches is also
desirable for a better understanding of the plant response to genotoxic stress. De-
spite the availability of innovative and high throughput technologies such as DNA
microarray and protein profiling, till date only a limited number of DNA repair
genes has been clearly demonstrated to be stress-responsive.
Information derived from model organisms will be translated in practical appli-
cations directed toward agronomically relevant species and varieties, as it would be
in the case of the model legume
Medicago truncatula
and the valuable
Medicago
sativa
accessions. The urgency for fulfilling all these specific goals is quite evident.
References
Achary VMM, Panda BB (2010) Aluminum-induced DNA damage and adaptive response to geno-
toxic stress in plant cells are mediated through reactive oxygen intermediates. Mutagenesis
25:201-209
