Diffusion pathway for oxygen into highly thermogenic florets of the, arum lily Philodendron selloum
Diffusion pathway for oxygen into highly thermogenic florets of the, arum lily Philodendron selloum
复制标题
DOI：
10.1093/jexbot/52.360.1465
复制
发表时间：
2001-07-01
影响因子：
6.9
通讯作者：
Seymour, RS
中科院分区：
文献类型：
--
作者：
Seymour, RS
一些海芋百合的产热花序是已知植物中呼吸速率最高的。当花序温度升高到38℃时，菲罗丹（Philodendron selloum Koch）不育雄花的耗氧量峰值超过0.3 μ mol s(-1) g（-1）。本研究描述了大气与小花实质细胞间氧扩散途径的形态。小花、气孔、间质气体网络和细胞的尺寸为“氧级联”各水平P-O2分布的扩散模型提供了数据。小花最厚部分轴线处P-O2最小值为4.7 kPa (35 mmHg)，表明最大呼吸未达到扩散限制点，证实了早期生理测量的耗氧速率对环境Po的依赖性。尽管气孔密度小于叶片中常见值的5%，间隙气体分数小于2%，但适当的小花大小可以使所有细胞充分通气。
Thermogenic inflorescences of some arum lilies have the highest rates of respiration known among plants. Peak rates of oxygen consumption in the sterile male florets of Philodendron selloum Koch exceed 0.3 mu mol s(-1) g(-1) when the inflorescence warms to 38 degreesC. This study describes the morphology of the oxygen diffusion pathway between the atmosphere and the parenchymal cells of the florets. Dimensions of the florets, stomata, interstitial gas network, and cells provide data for diffusion models of the P-O2 profiles at each level of the 'oxygen cascade'. The lowest calculated P-O2 of 4.7 kPa (35 mmHg) at the axis of the thickest part of the floret indicates that maximum respiration does not reach the point of diffusion-limitation, confirming earlier physiological measurements of the dependence of oxygen consumption rate on environmental Po.. Adequate aeration of all cells is achieved by appropriate floret size, despite a stomatal density less than 5%, and interstitial gas fraction less than 2%, of values commonly found in leaves.