Robust estimates of cuticle conductance on stomatous leaf surfaces during the light induction of photosynthesis
Robust estimates of cuticle conductance on stomatous leaf surfaces during the light induction of photosynthesis
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光合作用光诱导过程中气孔叶表面角质层电导的稳健估计
DOI：
10.1101/2020.05.28.120030
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Hanson David T.
中科院分区：
文献类型：
--
作者：
Tominaga Jun;Stinziano Joseph R.;Hanson David T.
当气孔导度（gsw）较小时，角质层导度（gcw）会使叶片内细胞间CO2浓度（Ci）的计算产生偏差。我们通过直接测量Cia以及向日葵和烟草叶片中的标准气体交换来研究光合作用的光诱导如何影响计算。当光合作用从暗光诱导到饱和光（1200 μmol m−2s−1PAR）时，计算出的Ci明显大于测量的Ci，并且差异减小asgwin 增加。这种差异可能导致光合作用早期诱导期间有限的 CO2 供应导致 rubisco 失活的高估。然而，在阴影诱导期间（50 μmol m−2s−1PAR），仅观察到 Ci 的微小差异，因为 gsw 足够大。与直接 Ci 测量相结合时，来自黑暗的感应还可以对 gcw 进行可靠的估计。这些估计成功地纠正了计算，表明角质层是误差的主要来源。尽管对两气孔叶存在技术限制，但所提出的技术有可能提供对完整气孔叶表面的角质层电导的深入了解。
Cuticle conductance (gcw) can bias calculations of intercellular CO2concentration inside the leaf (Ci) when stomatal conductance (gsw) is small.We examined how the light induction of photosynthesis impacts calculations by directly measuringCialong with standard gas exchange in sunflower and tobacco leaves.When photosynthesis was induced from dark to saturating light (1200 μmol m−2s−1PAR) the calculatedCiwas significantly larger than measuredCiand the difference decreased asgswincreased. This difference could lead to over-estimation of rubisco deactivation by limited CO2supply during early induction of photosynthesis. However, only small differences inCiwere observed during the induction from shade (50 μmol m−2s−1PAR) becausegswwas sufficiently large. The induction from dark also allowed robust estimations ofgcwwhen combined with directCimeasurements. Thesegcwestimates succeeded in correcting the calculation, suggesting that the cuticle was the major source of error.Despite a technical restriction to amphi-stomatous leaves, the presented technique has a potential to provide insights into the cuticle conductance on intact stomatous leaf surfaces.