Thus, modulation of their
activity is genetically accessible and, in contrast to primary
apical meristems, the existence of extreme cases can be expected. In this context, it is interesting to note that dramatic
differences in SL levels and shoot architecture among different rice strains have been recently reported (Jamil et al.,
2012). As soon as one appropriate environmental factor that
influences the activity of several types of meristems and
which can be tightly controlled under laboratory conditions
has been identified, such an approach becomes feasible.
Potentially, existing computational models might be exploited
for visualizing the outcome of molecular variation. For example, models have described the process of bud activation and
its relationship to auxin transport (Prusinkiewicz et al., 2009;
Prusinkiewicz and Runions, 2012; Renton et al., 2012). To date
there is no model describing lateral growth, let alone the
interaction between lateral growth and branching. However,
combining natural variation data from both processes in a
computational model could be useful to study the benefits
of coordinated developmental flexibility.
Questions that can be addressed by following such approaches are whether there is general coordination in the
AM and vascular cambium activity, and to what degree this
is genetically determined and evolutionarily meaningful. Current bio-statistics techniques, such as the application of
GWAS, are powerful tools that can investigate the genetics
of adaptation and address the evolutionary impact of trait–
to-loci association. These analyses are especially powerful
when applied to selfing plants like Arabidopsis thaliana, where it is possible to measure the same trait for the same genotype
in distinct environmental conditions (Atwell et al., 2010).
Thus, the application of GWAS to natural variation studies
on axillary bud and cambium activities of Arabidopsis under
changing environmental conditions might be an ideal system,
not only to unravel important aspects of the genetic basis of
plant architecture regulation, but also to approach the concept of the role of phenotypic plasticity in driving such
adaptation.