“光和K^+对气孔开度的影响”实验设计再优化  

Experimental design reoptimization for “The effects of light and K^+ on stomatal opening”

作　　者：王萍 邱念伟[1] 侯文雨 宋晓旭 舒凤月[1] 周峰 WANG Ping;QIU Nianwei;HOU Wenyu;SONG Xiaoxu;SHU Fengyue;ZHOU Feng(School of Life Sciences,Qufu Normal University,Qufu,Shandong 273165,China;School of Food Science,Nanjing Xiaozhuang University,Nanjing 211171,China)

机构地区：[1]曲阜师范大学生命科学学院,山东曲阜273165 [2]南京晓庄学院食品科学学院,南京211171

出　　处：《植物生理学报》2020年第4期779-788,共10页Plant Physiology Journal

基　　金：江苏省高等学校自然科学研究重大项目(19KJA310009);国家自然科学基金(31672255);国家大学生创新创业训练计划项目(201810446041)。

摘　　要：K+积累学说是气孔运动最普遍的机制。为验证K+积累学说,经典的方法是将叶片表皮分别浸泡于0.5%KNO3、0.5%NaNO3溶液和蒸馏水中照光,观察并比较气孔开度。此法虽多次改进,仍存在着各处理间的气孔开度差异不够显著、不能准确测定气孔开度大小、保卫细胞的结构不清晰等问题。本文从材料选取、对照设置、实验前的暗处理、诱导气孔开放的方法和光照条件等方面对该实验进一步优化,证明紫鸭跖草(Commelina purpurea)叶片下表皮是理想的观察气孔运动的材料,其气孔较大、保卫细胞结构清晰,可在黑暗条件下快速关闭气孔,在光下快速开放气孔,能准确测量其气孔开度。使用与叶片细胞等渗的蔗糖溶液代替蒸馏水作为空白对照,用等渗的NaNO3作为阴性对照,照光后两个对照的气孔均未显著开放,在等渗KNO3中的气孔则开度较大,更能充分说明K+在气孔运动中的作用。将紫鸭跖草叶片下表皮向上浸泡于等渗的上述溶液中照光,撕取下表皮制成临时装片观察气孔开度,效果好于传统的下表皮直接浸泡法,在200μmol·m-2·s-1光强下照光0.5 h即可观察到理想的实验效果。上述改进为植物生理实验教学及气孔运动研究提供了新方法。The K+ accumulation theory is the most common stomatal movement mechanism in plants. To verify the K+ accumulation theory, the most classic method is to soak the leaf epidermis in 0.5% KNO3, 0.5% NaNO3 solution and distilled water to observe and compare the stomatal aperture. Although this method has been improved many times, the difference in stomatal aperture among treatments is still not significant enough. The size of the stomatal opening cannot be accurately determined, and the structure of the guard cells is not clear. This paper further optimized this experiment from the aspects of material selection, control setting, dark treatment before experiment, treatment methods and light conditions for inducing stomatal opening. Leaf lower epidermis of Commelina purpurea was proved to be an ideal material for observing stomatal movement, with large stomata and clear cell structure. C. purpurea could quickly close the stomata in the dark, and open the stomata quickly under light. The stomatal aperture could be measured accurately. After illuminating, the stomata of C. purpurea were not open or the aperture was extremely small under the blank control condition of isotonic sucrose solution(instead of distilled water) and the negative control condition of isotonic NaNO3 solution, while the stomata widely opened in the isotonic KNO3 solution. This result could fully explain the role of K+ in stomatal movement. Soaking the leaves with the lower epidermis upturned in above isotonic solution was better than soaking the lower epidermis directly. The former could observe the ideal experimental effect under the illumination intensity of 200 μmol·m-2·s-1 for only 0.5 h. The above improvements provide a new method for plant physiological experiment teaching and stomatal movement research.

关 键 词：气孔 紫鸭跖草 钾离子 等渗溶液 光照 暗处理 

分 类 号：Q945-33[生物学—植物学]