[Choline chloride protects cell membrane and the photosynthetic apparatus in cucumber seedling leaves at low temperature and weak light].
Choline chloride 1.07 mmol/L treatment diminished the saturated lipid contents of the fatty acid components mainly the phosphatidylglycerol (PG) resulting in the decrease of the saturation of lipid (Table 1), declined the permeability of cell membrane and the production of MDA from lipid peroxidation (Fig.2) in the cucumber seedling leaves under low temperature and weak light (6 degrees C, PFD 100 micromol m(-2) s(-1)). Furthermore, the choline chloride treatment alleviated the degradation of chlorophyll pigments especially chlorophyll b, the decrease in maximum photochemical efficiency (Fv/Fm), the capture efficiency of excited energy (Fv'/Fm'), the photochemical quenching coefficient (q(p)) and the actual photochemical efficiency (Phi PSII) of PSII (Table 2, Fig.3A, B & C), and decreases in activity of antioxidant enzymes such as POD, APX and CAT (Fig.4) in chilled leaves under weak light. In addition, choline chloride treatment increased the non-photochemical quenching (NPQ) (Fig.3D) and the proline content (Fig.5) in chilled leaves under weak light. The above results indicate that choline chloride protected the cell membrane and the photosynthetic apparatus in cucumber seedling leaves from chilling stress in weak light.
Department of Plant Science, Shandong Agricultural University, Tai'an 271018, China.
Rui-Yan
RY
Sheng
Peng-Min
PM
Li
Guo-Xi
GX
Xue
Xin-Xi
XX
Zhao
Hui-Yuan
HY
Gao
D002118:Calcium / Q000378:metabolism; D002462:Cell Membrane / Q000187:drug effects*; D002712:Chlorides / Q000633:toxicity*; D002734:Chlorophyll / Q000502:physiology; D003080:Cold Temperature; D018553:Cucumis sativus / Q000187:drug effects* / Q000254:growth & development; D008027:Light; D045322:Photosynthetic Reaction Center Complex Proteins / Q000187:drug effects* / Q000378:metabolism; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D011188:Potassium / Q000378:metabolism; D036226:Seedlings / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism; D012964:Sodium / Q000378:metabolism
D002712:Chlorides; D045322:Photosynthetic Reaction Center Complex Proteins; D002734:Chlorophyll; D012964:Sodium; D011188:Potassium; D002118:Calcium; C001599:chlorite