重金属铊胁迫羽衣甘蓝的in situ-ATR-FTIR表征

Characterization of Kale(Brassica Oberacea var Acephala) under Thallium Stress by In Situ Attenuated Total Reflection FTIR

通过植物叶片光合作用消耗二氧化碳实验,实现了羽衣甘蓝光合作用的原位衰减全反射红外光谱表征。结果表明,羽衣甘蓝无论是否受到铊胁迫,其吸收峰的位置均无明显改变,其中3380 cm-1处的强吸收峰表征叶片中的水分,碳水化合物,蛋白质和酰胺化合物等;2916,2850 cm-1处的强峰以及2960 cm-1处的肩峰表征碳水化合物和脂肪族化合物等;1640 cm-1处的吸收峰表征水分。然而,通过对羽衣甘蓝叶片进行原位表征,发现表征CO2的2360和2340 cm-1双吸收峰("负峰")均从无到有,逐渐增强,说明羽衣甘蓝在进行光合作用。并且,铊胁迫组叶片二氧化碳的消耗速率明显高于空白样,即一定浓度铊胁迫会提高羽衣甘蓝的光合速率,表明羽衣甘蓝对重金属铊具有耐受的特性;结果也表明成年叶光合作用强度大于幼叶,这符合植物叶片光合作用的一般规律。

The experiment was designed based on consumption of carbon dioxide through the photosynthesis of Brassica oberacea var acephala leaf,and the photosynthesis of kale leaf under thallium stress was investigated by in situ attenuated total reflection FTIR（in situ ATR-FTIR）.The ATR-FTIR showed that the absorption peaks of leaves had no obvious difference between plants growing in thallium stress soil and plants growing in non-thallium pollution soil,and the strong peaks at 3 380 cm^-1 could be assigned to the absorption of water,carbohydrate,protein or amide;the strong peaks at 2 916 and 2 850 cm^-1 assigned to the absorption of carbohydrate or aliphatic compound;the peaks at 1 640 cm^-1 assigned to the absorption of water.However,as detected by the in situ ATR-FTIR,the double peaks（negative peaks） at 2 360 and 2 340 cm^-1 that are assigned to the absorption of CO2 appeared and became high gradually.It was showed that kale was carrying photosynthesis.At the same time,the carbon dioxide consumption speed of leaf under thallium stress was obviously larger than that of the blank.It was expressed that photosynthesis under thallium stress was stronger than the blank.All these represented that kale had certain tolerance to the heavy metal thallium.Meanwhile, the carbon dioxide consumption of grown-up leaf was more than that of young leaf whether or not under thallium stress.It was also indicated that the intensity of photosynthesis in grown-up leaf is higher than that in young leaf.