培养基磷缺乏对黄瓜毛状根生长、抗氧化酶活性及氮源利用的影响

Influences of Phosphate Deficiency in the Medium on Growth, Activities of Antioxidant Enzymes and Utilization of Nitrogen Resource in Cucumis sativus Hairy Roots

摘要:

采用液体培养的方法研究了培养基磷缺乏对黄瓜毛状根生长及其抗氧化酶活性及培养基中氮源和钙利用的影响。结果表明, 黄瓜毛状根在完全缺磷的培养基中几乎不能生长; 而培养基无机磷缺乏会抑制黄瓜毛状根的生长, 且浓度越低, 其抑制作用越明显, 毛状根变得越纤细而长, 侧根数减少且短小。与全磷培养相比, 磷缺乏培养基培养的黄瓜毛状根可溶性蛋白含量明显偏低, 但其SOD和POD活性则明显升高。与完全缺磷(对照)相比, 在培养过程中不同无机磷浓度培养的黄瓜毛状根的SOD和POD活性均比对照低。当黄瓜毛状根在不同磷缺乏浓度的液体培养基中培养时, 随着培养时间的延长, 培养基的电导率逐步下降, 并与培养基起始无机磷浓度成正比; 其培养基的铵态氮和硝态氮不断被吸收和利用, 培养至15d时, 培养基中的铵态氮已绝大部分被消耗完毕, 但直至培养30d时培养基的硝态氮仍未被消耗完毕。培养基中无机磷缺乏会降低黄瓜毛状根对培养基硝态氮的吸收和消耗以及抑制黄瓜毛状根对钙的吸收。而适当提高培养基的无机磷浓度可促进黄瓜毛状根对培养基中钙的吸收和消耗。

Abstract:

Effects of phosphorus deficiency in the medium on growth and morphology and activities of SOD and POD, utilization of nitrogen and calcium in the medium during liquid culture of Cucumis sativus hairy roots were investigated. The results showed that C. sativus hairy roots can not grow in the medium without addition of any phosphorus. When cultured into the medium with different Pi concentrations, the growth of C. sativus hairy roots was significantly inhibited with the decreasing of Pi concentration in the medium, its main roots became thinner and longer, the number of its lateral roots was decreased and its lateral roots became shorter and smaller. Compared to the medium with full strength phosphorus, the content of soluble proteins in C. sativus hairy roots cultured under Pi deficiency was significantly lower than that with standard full-length Pi, while POD and SOD activities in C. sativus hairy roots were significantly stimulated. Compared to the control (without addition of any phosphorus in the medium), the activities of POD and SOD in C. sativus hairy roots cultured in the medium with different concentration of Pi were lower than the control. When C. sativus hairy roots were cultured into medium with different Pi concentrations, the medium conductivity was gradually decreased with time and with direct proportion of the initial Pi concentration of the medium; NH4+-N and NO3--N of the medium was gradually absorbed and utilized, at day 15, NH4+-N of the medium was nearly used up but its NO3--N was not used up until cultured for 30 days. Pi deficiency in the medium could decrease the consumption rate of NO3--N and inhibited the absorption and utilization of calcium of the medium by C. sativus hairy roots. Proper enhancement of Pi concentration could stimulate absorption and consumption of calcium of the medium.