CAJ | 학술논문

两种不同基因型小麦京411(J411,北京地区高产小麦品种)和小偃54(X54,一种远源杂交品种)的光合作用对低浓度NaHSO3处理的响应不同.NaHSO3 1 mmol/L处理能够提高京411在CO2浓度为350和900 μL/L的空气中的净光合速率;而对小偃54,在这两种情况下的净光合速率均无明显影响.以往的研究表明NaHSO3促进光合作用的原因类似于PMS(phenazine methosulfate),都是增加了ATP的合成.此文再次证明并发现经过NaHSO3 1 mmol/L处理后,京411叶片作用光关闭后叶绿素荧光瞬时上升的幅度提高,远红光后P700+(reaction center chlorophyll of PSI)再还原的半时间缩短,表明NaHSO3 可以促进小麦京411中围绕PSI循环电子传递及其耦联的磷酸化.然而,NaHSO3 对小偃54的作用光关闭后叶绿素荧光瞬时上升的幅度及远红光后P700+再还原的半时间均无明显影响.与小麦京411相比较,小偃54的作用光停止后叶绿素荧光瞬时上升的幅度增大,而且其在远红光后P700+再还原的半时间更短,表明小偃54的循环电子传递的能力远高于京411的.两种不同基因型小麦对NaHSO3的响应不同很可能是由于二者在循环电子传递能力上有很大的差别.
량충불동기인형소맥경411(J411,북경지구고산소맥품충)화소언54(X54,일충원원잡교품충)적광합작용대저농도NaHSO3처리적향응불동.NaHSO3 1 mmol/L처리능구제고경411재CO2농도위350화900 μL/L적공기중적정광합속솔;이대소언54,재저량충정황하적정광합속솔균무명현영향.이왕적연구표명NaHSO3촉진광합작용적원인유사우PMS(phenazine methosulfate),도시증가료ATP적합성.차문재차증명병발현경과NaHSO3 1 mmol/L처리후,경411협편작용광관폐후협록소형광순시상승적폭도제고,원홍광후P700+(reaction center chlorophyll of PSI)재환원적반시간축단,표명NaHSO3 가이촉진소맥경411중위요PSI순배전자전체급기우련적린산화.연이,NaHSO3 대소언54적작용광관폐후협록소형광순시상승적폭도급원홍광후P700+재환원적반시간균무명현영향.여소맥경411상비교,소언54적작용광정지후협록소형광순시상승적폭도증대,이차기재원홍광후P700+재환원적반시간경단,표명소언54적순배전자전체적능력원고우경411적.량충불동기인형소맥대NaHSO3적향응불동흔가능시유우이자재순배전자전체능력상유흔대적차별.
Two wheat genotypes, Jing 411(J411, a high-yield cultivar cultivated around Beijing area) and Xiaoyan 54 (X54, a wheat cultivar formed by crossing Triticum aestivum L. with Elytrigia elongatiformis), were found to give different responses of photosynthesis to treatment with low concentration of sodium bisulfite (NaHSO3). Bisulfite 1 mmol/L increased net photosynthetic rate (Pn) in wheat J411 under CO2 concentrations of both 350 and 900 μL/L, but there was no significant enhancement of Pn in wheat X54 under either condition. In previous studies the effects of bisulfite in increasing Pn in wheat J411 and rice have been shown to be similar to that of PMS, both through an increase in the supply of ATP and this has been confirmed and investigated in the present study in wheat J411. In parallel with the increases in Pn and ATP content, the post-illumination transient increase in chlorophyll fluorescence was enhanced and the half-time of re-reduction of P700+ after illumination with far-red light was significantly shortened in leaves of wheat J411 after treatment with bisulfite 1 mmol/L, indicating that cyclic electron flow around PSI and the coupled photophosphorylation (PSP) were accelerated. In contrast, bisulfite had no effect on either the post-illumination transient increase in chlorophyll fluorescence or the half-time of re-reduction of P700+ after a far-red light in wheat X54. It was also found that the intensity of the post-illumination transient increase in chlorophyll fluorescence was much higher, and the half-time of re-reduction of P700+ was much shorter in wheat X54 than those in J411, suggesting that wheat X54 had higher intrinsic cyclic electron transport around PSI than that in J411. Basing on these results, it is suggested that the enhancement of Pn in higher plants by low concentrations of bisulfite solution might be due to the stimulation of cyclic electron flow around PSI and hence the PSP coupled to it. The difference in response to bisulfite between the two wheat genotypes could be attributed to the significant difference in rate of intrinsic cyclic electron transport around PSI between them.