磷对铝胁迫油茶芽苗初生根保护酶的影响

Effects of phosphorus on protective enzymes in primary roots of Camellia oleifera seedlings under aluminum stress

[目的]研究不同浓度磷对铝胁迫下油茶芽苗初生根的生长和生理活性的影响,为磷缓解铝胁迫的生理机制和油茶耐铝特性提供了理论依据。[方法]以“岑软2号”油茶种子为试验材料,采用水培实验设置了5个水平:全铝(Al,4 mmol/L Al)、全铝+低磷(P1,1 mmol/L P)、全铝+中磷(P2,2 mmol/L P)、全铝+高磷(P4,4 mmol/L P)以及无磷铝(CK)作为对照,在处理周期内的第0、1、3、5和7天分别测定不同处理下油茶芽苗初生根的超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、超氧阴离子自由基(O2-)理化性质指标,并每天测定生长长度,计算根相对生长率。[结果]Al处理相对生长率为52.81%,根系SOD活性降低,O2-含量升高,POD和CAT活性增加;P1处理根相对生长率可达144.42%,SOD活性显著高于P2、P4和Al处理组(P <0.05),O2-含量显著低于Al处理组(P <0.05),POD和CAT水平显著低于Al处理组(P <0.05);P2处理根相对生长率在处理周期内均低于100%,POD活性显著高于CK处理组,SOD活性显著低于CK处理组,CAT活性显著低于Al处理组;P4处理组中根相对生长率仅有27.32%,SOD和CAT活性受到抑制,POD活性和O2-含量升高。[结论]在4 mmol/L铝胁迫的情况下,添加1 mmol/L磷对油茶芽苗初生根的缓解作用更好。

【Objective】The effects of different concentrations of phosphorus on the growth and physiological activity of primary roots of Camellia oleifera seedlings under aluminum stress were studied,which provided a theoretical basis for the physiological mechanism of phosphorus alleviating aluminum stress and the aluminum tolerance of C.oleifera.【Method】Using‘Cenruan 2’C.oleifera seeds as the experimental material,and a hydroponic experiment was conducted with five levels:full aluminum(Al,4 mmol/L Al),full aluminum+low phosphorus(P1,1 mmol/L P),full aluminum+medium phosphorus(P2,2 mmol/L P),full aluminum+high phosphorus(P4,4 mmol/L P),and no phosphorus and aluminum(CK)as the control.The superoxide dismutase(SOD),peroxidase(POD),catalase(CAT),and physicochemical properties of superoxide anion(O2-)of the primary roots of C.oleifera seedlings under different treatments were determined on 0 d,1 d,3 d,5 d,and 7 d during the treatment period.The growth length was measured each day,and the relative root elongation was calculated.【Result】The relative root elongation under Al treatment was 52.81%,and the SOD activity of the root system was reduced,while the O2-content increased,and the POD and CAT activities increased.The relative root elongation under P1 treatment reached 144.42%,and the SOD activity was significantly higher than that of the P2,P4,and Al treatment groups-(P<0.05),while the O2 content was significantly lower than that of the Al treatment group(P<0.05),and the POD and CAT levels were significantly lower than those of the Al treatment group(P<0.05).The relative root elongation under P2 treatment was consistently less than 100%during the treatment period,and the POD activity was significantly higher than that of the CK treatment group,while the SOD activity was significantly lower than that of the CK treatment group,and the CAT activity was significantly lower than that of the Al treatment group.The relative root elongation under P4 treatment-was only 27.32%,and the SOD and CAT activities were inhibited,while the POD activity and O2 content increased.【Conclusion】Under the condition of 4 mmol/L aluminum stress,adding 1 mmol/L phosphorus had a better alleviating effect on the primary roots of C.oleifera seedlings.