CHALKER-SCOTT, LINDA K. Center for Urban Horticulture, Box 354115, University of Washington, Seattle, WA 98195. - Do anthocyanins function as osmoregulators in leaf tissues?
Water stress can be induced in plant tissues, directly or indirectly,
by a number of environmental conditions. Plants exposed to drought,
heat, cold, wind, flooding, or saline conditions often synthesize
foliar anthocyanins in response. Although previously thought to
function as a UV screen, anthocyanins may instead serve to decrease
leaf osmotic potential. This depression of leaf water potential could
increase water uptake and/or reduce transpirational losses. Combined
with other anti-stress activities attributed to anthocyanins
(including their solar shield and antioxidative capacities), this
phenomenon may allow anthocyanin-containing leaves to tolerate
suboptimal water levels. Preliminary information linking leaf
anthocyanin content to dehydration tolerance of several species will
be presented.
Key words: drought, resistance, stress