Maggio Albino, Chiarandà Fabrizio Quaglietta, Cefariello Roberto, Fagnano Massimo
DIAAT, Naples University Federico II, via Università 100, 80055 Portici (NA), Italy.
Environ Pollut. 2009 May;157(5):1445-52. doi: 10.1016/j.envpol.2008.09.013. Epub 2008 Nov 1.
Stomatal closure and biosynthesis of antioxidant molecules are two fundamental components of the physiological machinery that lead to stress adaptation during plant's exposure to salinity. Since high stomatal resistance may also contribute in counteracting O(3) damages, we hypothesized that soil salinization may increase O(3) tolerance of crops. An experiment was performed with alfalfa grown in filtered (AOT40=0 in both years) and non-filtered (AOT40=9.7 in 2005 and 6.9 ppm h in 2006) open-top chambers. Alfalfa yield was reduced by O(3) (-33%) only in plants irrigated with salt-free water, while the increasing levels of soil salinity until 1.06 dS m(-1) reduced both stomatal conductance and plant O(3) uptake, thus linearly reducing O(3) effects on yield. Therefore a reliable flux-based model for assessing the effects of O(3) on crop yield should take into account soil salinity.
气孔关闭和抗氧化分子的生物合成是植物在盐胁迫下实现应激适应的生理机制中的两个基本组成部分。由于高气孔阻力也可能有助于抵消臭氧的损害，我们推测土壤盐渍化可能会提高作物对臭氧的耐受性。实验使用在过滤（两年中AOT40均为0）和未过滤（2005年AOT40为9.7，2006年为6.9 ppm·h）的开顶式气室中种植的苜蓿进行。仅在用无盐水灌溉的植株中，臭氧使苜蓿产量降低了33%，而土壤盐分含量增加至1.06 dS m-1时，气孔导度和植株对臭氧的吸收均降低，从而线性降低了臭氧对产量的影响。因此，一个可靠的基于通量的评估臭氧对作物产量影响的模型应考虑土壤盐分。
