E. Gianoli et Hm. Niemeyer, ENVIRONMENTAL-EFFECTS ON THE ACCUMULATION OF HYDROXAMIC ACIDS IN WHEAT SEEDLINGS - THE IMPORTANCE OF PLANT-GROWTH RATE, Journal of chemical ecology, 23(2), 1997, pp. 543-551
The effects of temperature and photoperiod on accumulation of hydroxam
ic acids (Hx) in wheat (Triticum aestivum L.) seedlings were evaluated
under laboratory conditions. Hx concentrations were significantly hig
her at higher temperatures. No such clear trend was found for the phot
operiod effect. The significant effect of temperature and photoperiod
on growth rate of seedlings and the significant positive correlation b
etween growth rate prior to analysis and levels of Hx, suggested that
environmental effects on Hx accumulation were at least partially media
ted through their effect on plant growth rate. After uncoupling the ef
fect of environmental conditions from the effect of plant growth rate
by statistical means the effect of temperature on Hx was no longer sig
nificant. Therefore, temperature effect was fully mediated by plant gr
owth rate. Implications of the patterns found are discussed in issues
of plant-defense general theories.