Division of Plant Biology, Department of Biosciences, University of Helsinki, FI-00014 Helsinki, Finland.
Plant Cell Environ. 2010 Jun;33(6):914-25. doi: 10.1111/j.1365-3040.2010.02116.x. Epub 2010 Jan 15.
Genetic variation between naturally occurring populations provides a unique source to unravel the complex mechanisms of stress tolerance. Here, we have analysed O(3) sensitivity of 93 natural Arabidopsis thaliana accessions together with five O(3)-sensitive mutants to acute O(3) exposure. The variation in O(3) sensitivity among the natural accessions was much higher than among the O(3)-sensitive mutants and corresponding wild types. A subset of nine accessions with major variation in their O(3) responses was studied in more detail. Among the traits assayed, stomatal conductance (g(st)) was an important factor determining O(3) sensitivity of the selected accessions. The most O(3)-sensitive accession, Cvi-0, had constitutively high g(st), leading to high initial O(3) uptake rate and dose received during the first 30 min of exposure. Analyzing O(3)-induced changes in stress hormone concentrations indicated that jasmonate (JA) concentration was also positively correlated with leaf damage. Quantitative trait loci (QTL) mapping in a Col-0 x Cvi-0 recombinant inbred line (RIL) population identified three QTLs for O(3) sensitivity, and one for high water loss of Cvi-0. The major O(3) QTL mapped to the same position as the water loss QTL further supporting the role of stomata in regulating O(3) entry and damage.
自然发生的种群之间的遗传变异为揭示应激耐受的复杂机制提供了独特的来源。在这里，我们分析了 93 个天然拟南芥品系以及五个 O(3)敏感突变体对急性 O(3)暴露的敏感性。与 O(3)敏感突变体和相应的野生型相比，天然品系之间的 O(3)敏感性变异要高得多。对一组 9 个 O(3)反应差异较大的品系进行了更详细的研究。在所测定的特性中，气孔导度（g(st)）是决定所选品系 O(3)敏感性的重要因素。最敏感的品系 Cvi-0 具有较高的 g(st)，导致在暴露的前 30 分钟内吸收初始 O(3)的速率和剂量较高。分析 O(3)诱导的应激激素浓度变化表明，茉莉酸（JA）浓度也与叶片损伤呈正相关。在 Col-0 x Cvi-0 重组自交系（RIL）群体中进行的数量性状位点（QTL）作图确定了三个 O(3)敏感的 QTL，一个 Cvi-0 高水分损失的 QTL。主要的 O(3)QTL 与水分损失 QTL 映射到相同的位置，进一步支持了气孔在调节 O(3)进入和损伤中的作用。
