Data from: Consistent alleviation of abiotic stress with silicon addition: a meta-analysis

Hundreds of single species studies have demonstrated the facility of
silicon (Si) to alleviate diverse abiotic stresses in plants.
Understanding of the mechanisms of Si-mediated stress alleviation is
progressing, and several reviews have brought information together. A
quantitative assessment of the alleviative capacity of Si, however, which
could elucidate plant Si function more broadly, was lacking. We combined
the results of 145 experiments, predominantly on agricultural species, in
a meta-analysis to statistically assess the responses of stressed plants
to Si supply across multiple plant families and abiotic stresses. We
interrogated our database to determine whether stressed plants increased
in dry mass and net assimilation rate, oxidative stress markers were
reduced, antioxidant responses were increased and whether element uptake
showed consistent changes when supplied with Si. We demonstrated that
across plant families and stress types, Si increases dry weight,
assimilation rate and chlorophyll biosynthesis and alleviates oxidative
damage in stressed plants. In general, results indicated that plant family
(as a proxy for accumulator type) and stress type had significant
explanatory power for variation in responses. The consistent reduction in
oxidative damage was not mirrored by consistent increases in antioxidant
production, indicative of the several different stress alleviation
mechanisms in which Si is involved. Silicon addition increased K in
shoots, decreased As and Cd in roots and Na and Cd in shoots. Silicon
addition did not affect Al, Ca or Mn concentration in shoots and roots of
stressed plants. Plants had significantly lower concentrations of Si
accumulated in shoots but not in roots when stressed. Meta-analyses showed
consistent alleviation by Si of oxidative damage caused by a range of
abiotic stresses across diverse species. Our findings indicate that Si is
likely to be a useful fertilizer for many crops facing a spectrum of
abiotic stresses. Similarities in responses across families provide strong
support for a role of Si in the alleviation of abiotic stress in natural
systems, where it has barely been explored. We suggest this role may
become more important under a changing climate and more experiments using
non-agricultural species are now needed.