Zhang Zi-Shan, Yang Cheng, Gao Hui-Yuan, Wang Wei-Wei, Sun Xue-Juan, Meng Xiang-Long, Meng Qing-Wei
State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, Shandong, China.
Ying Yong Sheng Tai Xue Bao. 2012 Apr;23(4):1049-54.
Taking Cucumis sativus L. (Jinchun No. 4) as test material, through the determination of chlorophyll-a fluorescence transient and light absorbance at 820 nm, and in combining with chlorophyll quenching, this paper studied the recovery of cucumber leaf' s PS I and PS I activities and the interactions between PS I and PS II in the recovery process at room temperature (25 degrees C) and under different light intensities (0, 15, and 200 micromol x m(-2) x s(-1)) after six hours of low temperature (4 degrees C) and strong light (200 micromol x m(-2) x s(-1)) stress. Different extent of photoinhibition of the PS II and PS I occurred after the stress. During the recovery process at room temperature, the PS II activity recovered quickly and was insensitive to light intensity, while the PS I activity recovered quickly under weak light intensity (15 micromol x m(-2) x s(-1)) but slowly under strong light intensity (200 micromol x m(-2) x s(-1)), suggesting that after the chilling-induced photoinhibition, the reduced electron transfer from PS II to PS I protected the PS I from further inhibition, accelerating the recovery of PS I activity. In the breeding of chilling-resistant species of cucumber, it should not only pursue the higher chilling-resistance of PS II and faster recovery of PS II after chilling-induced photoinhibition, but also pay more attention to the coordinating of PS I and PS II during and after the chilling-induced photoinhibition. In the culture of cucumber, after chilling happened, a practical method to reduce light intensity would help the recovery of cucumber leaf PS I activity to protect the photosynthetic apparatus against photoinhibition.
以黄瓜（津春4号）为试验材料，通过测定叶绿素a荧光瞬变和820 nm处的光吸收，并结合叶绿素猝灭，研究了低温（4℃）强光（200 μmol·m⁻²·s⁻¹）胁迫6 h后，在室温（25℃）及不同光强（0、15和200 μmol·m⁻²·s⁻¹）下黄瓜叶片PSⅠ和PSⅡ活性的恢复以及PSⅠ与PSⅡ在恢复过程中的相互作用。胁迫后PSⅡ和PSⅠ发生了不同程度的光抑制。在室温恢复过程中，PSⅡ活性恢复迅速且对光强不敏感，而PSⅠ活性在弱光强（15 μmol·m⁻²·s⁻¹）下恢复迅速，在强光强（200 μmol·m⁻²·s⁻¹）下恢复缓慢，这表明冷害诱导的光抑制后，从PSⅡ到PSⅠ的电子传递减少保护了PSⅠ免受进一步抑制，加速了PSⅠ活性的恢复。在黄瓜抗冷品种选育中，不仅要追求PSⅡ较高的抗冷性和冷害诱导光抑制后PSⅡ较快的恢复，还要更加关注冷害诱导光抑制期间及之后PSⅠ与PSⅡ的协同作用。在黄瓜栽培中，冷害发生后，降低光强的实用方法有助于黄瓜叶片PSⅠ活性的恢复，保护光合机构免受光抑制。
