氧化石墨烯对多年生黑麦草逆境生理及光合特征的影响

Effects of graphene oxide on stress physiological and photosynthetic characteristics of Lolium perenne

关键词:  多年生黑麦草, 氧化石墨烯, 逆境生理, 氧化胁迫, 光合参数

Key words:  perennial ryegrass(Lolium perenne), graphene oxide(GO), stress physiology, oxidative stress, photosynthetic parameters

摘要:

为探讨不同浓度氧化石墨烯(GO)对多年生黑麦草生长、生理及光合特征的影响,该文采用盆栽试验,在土壤中添加0、10、20、30、40、50 mg·g^-1 GO进行多年生黑麦草培养,并测定植物生长指标、光合色素含量、保护酶活性、丙二醛(MDA)含量、叶片质膜透性、可溶性蛋白含量和光合参数。结果表明:(1)10、20 mg·g^-1 GO处理对多年生黑麦草生长无显著影响; 30～50 mg·g^-1 GO处理对多年生黑麦草生长具有抑制作用,在50 mg·g^-1 GO浓度下多年生黑麦草株高和生物量均最小,较对照分别降低了16.8%和27.1%。(2)当GO浓度达到30 mg·g^-1时,总叶绿素和类胡萝卜素的含量显著降低,在50 mg·g^-1 GO处理时达到最低。(3)高浓度的GO处理(40、50 mg·g^-1)虽降低了多年生黑麦草的叶片净光合速率(P_n)、气孔导度(G_s)和蒸腾速率(T_r),但增加了胞间CO₂浓度(C_i)。(4)低浓度的GO处理(10、20 mg·g^-1)对保护酶活性、丙二醛含量、叶片质膜透性和可溶性蛋白含量无显著影响,而高浓度的GO处理(40、50 mg·g^-1)使多年生黑麦草的超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性、MDA含量和叶片质膜透性显著升高,而可溶性蛋白含量则下降,植物叶片受到损伤。综上认为,高浓度的GO处理(40、50 mg·g^-1)会对多年生黑麦草产生氧化胁迫,从而抑制了植物的生长。

Abstract:

In order to explore the effects of graphene oxide(GO)with different concentrations on the growth, physiological and photosynthetic characteristics of perennial ryegrass(Lolium perenne)seedlings, a pot experiment was conducted by culturing perennial ryegrass in soil with treatments of GO in 0, 10, 20, 30, 40, 50 mg·g^-1 GO respectively. Parameters including plant growth, photosynthetic pigment contents, protective enzyme activity, malondialdehyde(MDA)content, leaf membrane permeability, soluble protein content as well as photosynthetic parameters were measured. The results were as follows:(1)No significant effects were detected on the growth of perennial ryegrass under 10, 20 mg·g^-1 GO treatments, however, 30-50 mg·g^-1 GO inhibited the perennial ryegrass growth. Under the 50 mg·g^-1 GO treatment, plant height and biomass of perennial ryegrass were the minimum in value, which were decreased by 16.8% and 27.1% compared with the control.(2)The contents of total chlorophyll and carotenoid decreased significantly when the concentration of GO reached 30 mg·g^-1, and the lowest value was found in 50 mg·g^-1 GO treatment.(3)High concentrations of GO(40, 50 mg·g^-1)decreased net photosynthetic rate(P_n), stomatal conductance(G_s)and transpiration rate(T_r), but increased the intercellular CO₂ concentration(C_i).(4)Low concentrations of GO(10, 20 mg·g^-1)had no significant effects on protective enzyme activity, MDA content, plasma membrane permeability and soluble protein content, while high concentrations of GO(40, 50 mg·g^-1)significantly increased superoxide dismutase(SOD), peroxidase(POD), catalase(CAT)activities, MDA content and plasma membrane permeability, decreased soluble protein content and damaged plant leaves. All the above results indicate that the addition of GO with high concentrations(40, 50 mg·g^-1)constitutes a stress on the growth of perennial ryegrass, thus inhibited plant growth.