School of Biological Sciences, University of Bristol, Woodland Road, Bristol BS8 1UG, UK.
Plant J. 2010 Nov;64(4):679-86. doi: 10.1111/j.1365-313X.2010.04362.x. Epub 2010 Oct 26.
To identify loci in Arabidopsis involved in the control of transpirational water loss and transpiration efficiency (TE) we carried out an infrared thermal imaging-based screen. We report the identification of a new allele of the Arabidopsis CesA7 cellulose synthase locus designated AtCesA7(irx3-5) involved in the control of TE. Leaves of the AtCesA7(irx3-5) mutant are warmer than the wild type (WT). This is due to reduced stomatal pore widths brought about by guard cells that are significantly smaller than the WT. The xylem of the AtCesA7(irx3-5) mutant is also partially collapsed, and we suggest that the small guard cells in the mutant result from decreased water supply to the developing leaf. We used carbon isotope discrimination to show that TE is increased in AtCesA7(irx3-5) when compared with the WT. Our work identifies a new class of genes that affects TE and raises the possibility that other genes involved in cell wall biosynthesis will have an impact on water use efficiency.
为了鉴定参与控制蒸腾失水和蒸腾效率（TE）的拟南芥基因座，我们进行了基于红外热成像的筛选。我们报告了一个新的拟南芥CesA7 纤维素合酶基因座的等位基因 AtCesA7(irx3-5)的鉴定，该基因座参与 TE 的控制。AtCesA7(irx3-5)突变体的叶片比野生型（WT）更温暖。这是由于保卫细胞的气孔孔径减小所致，而保卫细胞明显小于 WT。AtCesA7(irx3-5)突变体的木质部也部分塌陷，我们推测突变体中较小的保卫细胞是由于发育中的叶片供水减少所致。我们使用碳同位素分辨力来表明，与 WT 相比，AtCesA7(irx3-5)中的 TE 增加。我们的工作鉴定了一类新的基因，它们影响 TE，并提出了参与细胞壁生物合成的其他基因可能对水利用效率有影响的可能性。
