[Effects of short-term high temperature stress on flag leaf photosystem II functions of high-yielding wheat at late grain-filling stage].
By using fast OJIP chlorophyll a ( Chl a) fluorescence transients, this paper studied the effects of short-term high temperature stress on the flag leaf photosystem II (PS II ) functions of high-yielding winter wheat cultivar 01-35 at its late grain filling stage. The results showed that with the temperature raised from 37 degrees C to 43 degrees C , the extent and velocity of QA reduction enhanced gradually, being 23. 89% and 24. 09% higher at 43 degrees C than at room temperature, respectively, which suggested that the electron transport from QA to QB was inhibited. The electron acceptor pool of PS 1I including QA Q, and PQ at 43 degreesC decreased to 47. 4% of that at room temperature, indicating its being damaged. The electron donor side of PS II was not damaged from 37 degrees C to 43 degrees C. When temperature raised to 46 degrees C , the extent and velocity of QA reduction were 13. 95% and 20. 48% higher than those at room temperature, respectively, but decreased obviously, compared with those at 43 degrees C. In contrast, the electron acceptor pool of PS II at 46 degrees C had no obvious change, compared with that at 43 degrees C, indicating that the electron donor side of PS II at 46 TC was damaged. Comparing with cultivar Lumai 14, the light harvesting complex ( LHC U) of high-yielding wheat cultivar 01-35 could harvest more sun energy, and distributed more absorbed energy into electron transport, suggesting that the LHC II of cultivar 01-35 could endure a certain higher temperature, and maintain higher electron transport capacity.
Chen
Feng
F
College of Life Science, Shandong Agricultural University, Tai' an 271018, China. chf0509@126.com
Tian
Jichun
J
Meng
Qingwei
Q
Zhao
Shijie
S
D002523:Edible Grain / Q000254:growth & development*; D045332:Photosystem II Protein Complex / Q000737:chemistry / Q000502:physiology*; D018515:Plant Leaves / Q000378:metabolism / Q000502:physiology; D013696:Temperature; D013997:Time Factors; D014908:Triticum / Q000145:classification / Q000502:physiology*
D045332:Photosystem II Protein Complex