摘要
为了揭示烟草叶片光能利用和光保护系统在铝诱导的活性氧代谢中的作用机理,以2个不同耐铝性的烟草品种云烟100(耐铝)和云烟105(敏感)为材料,采用水培法研究了不同铝浓度(0,50,100,200μmol/L)对烟草植株生长、叶片活性氧含量、光合特性、叶绿素荧光参数、光呼吸、超氧化物歧化酶(SOD)和抗坏血酸过氧化物酶(APX)活性的影响。结果表明,铝浓度的升高显著降低了烟草叶片叶绿素含量、净光合速率(Pn)、最大光化学效率(Fv/Fm)、PSⅡ光合电子传递量子效率(ΦPSⅡ)和光化学猝灭系数(q P),提高了反应中心PSⅡ过剩激发能,从而导致叶片O_2-·和H2O_2含量升高,植株生物量下降,其中对云烟105影响大于云烟100。随铝处理浓度的升高,烟草叶片非光化学猝灭系数(NPQ)、光呼吸速率、SOD和APX活性呈先升后降的趋势。与敏感品种云烟105相比,耐铝品种云烟100在不同铝浓度胁迫下表现出更高的ΦPSⅡ、q P、NPQ、光呼吸速率以及SOD和APX活性,说明低浓度铝胁迫下烟草叶片可通过提高光化学反应能力、热耗散、光呼吸以及抗氧化酶活性等途径来降低反应中心PSⅡ过剩激发能,防止或清除活性氧的积累,从而增强其对铝的耐性。
In order to reveal the mechanism of tobacco leaf light energy utilization and photoprotective systems in aluminum （Al）-induced reactive oxygen species metabolism, two different Al-tolerant tobacco eultivars Yunyan 100 （Al-tolerant） and Yunyan 105 （Al-sensitive） were used to study effects of four Al concentrations （0, 50, 100, 200 μmol/L） on plant growth, reactive oxygen content, photosynthesis, chlorophyll fluorescence characteristics, photorespiration, activities of superoxide dismutase （SOD） and aseorbate peroxidase （APX） in leaves of to- bacco cultivar with solution culture method. The results showed that increasing AI concentrations significantly de- creased the leaf chlorophyll content, net photosynthetic rate （Pn）, maximal photochemical efficiency （Fv/Fm） , quantum yield of electron transport at PS II （ФpsⅡ） and coefficient of photochemical quenching （qP）, increased ex- cess energy of PS lI photochemistry leading to higher accumulation of leaf 02 ： and H202 , and lower plant biomass, especially in Yunyan 105. With the Al concentrations increased from 0 to 200 ixmol/L, the coefficient of non-photo- chemical quenching （NPQ） , photorespiration rate, and activities of SOD and APX were promoted firstly and then re- duced again. Compared with Al-sensitive cv. Yunyan 105, Al-tolerant cv. Yunyan 100 remained higher leaf ФPSⅡ, qP, NPQ, photorespiration rate, and activities of SOD and APX under different Al concentrations. These results indi- cated that tobacco could enhance the tolerance to Al stress by increasing photochemical reaction capacity, heat dissipation, photorespiration and activities of antioxidative enzymes in order to decrease excess energy of PS II photochem- istry, which prevents or eliminates reactive oxygen accumulation under the low A1 concentration.
出处
《华北农学报》
CSCD
北大核心
2017年第1期118-124,共7页
Acta Agriculturae Boreali-Sinica
基金
国家自然科学基金项目(31260498)
江西省教育厅科技项目(GJJ12466)
关键词
铝胁迫
活性氧
光合作用
叶绿素荧光
光呼吸
抗氧化酶
烟草
Aluminum stress
Reactive oxygen species
Photosynthesis
Chlorophyll fluorescence
Photorespira- tion
Antioxidant enzyme
Tobacco
