摘要
以粤糖55为材料,设6个锰处理水平,分别在正常水分和干旱条件下,通过桶栽试验,测定叶片的叶绿素、脯氨酸含量与Δ1-吡咯啉-5-羧酸合成酶(P5CS)和δ-鸟氨酸转氨酶(δ-OAT)活性及其基因表达。结果表明,随着施锰量的增加,2种水分条件下,所有测定指标均呈先增加后减小的趋势。干旱胁迫下,脯氨酸含量在锰浓度为0.8 g·kg^(-1)时达到最大;δ-OAT,P5CS活性与叶绿素含量在锰浓度为0.4 g·kg^(-1)时达到峰值;δ-OAT,P5CS基因表达量则是在0.2 g·kg^(-1)供锰条件下最大。正常水分下,叶绿素含量、脯氨酸含量、δ-OAT活性变化与干旱胁迫时相似;P5CS活性在0.8 g·kg^(-1)时达到最大,但增幅不大。统计分析结果表明,正常水分和干旱胁迫条件下,与脯氨酸含量的简单、偏相关系数和直接通径系数均达到极显著水平的分别是P5CS活性和δ-OAT活性。由此认为,在砖红壤土中,为保证甘蔗具有较强抗逆性,甘蔗的施锰量应为0.2~0.4 g·kg^(-1)。在锰的影响下,干旱胁迫时,甘蔗脯氨酸的合成途径以鸟氨酸途径为主;正常水分时,脯氨酸的合成则是谷氨酸途径更占优势。
In the present study, the sugarcane variety YT-55 was selected as study material. Under drought and nor-mal conditions, the activity of P5CS,δ-OAT and their gene expression, and contents of free proline and chlorophyll were tested under 6 Mn concentrations, respectively. It was shown that all indexes tested exhibited a first increasing and then decreasing trend with the elevated Mn application rates under two water conditions. Under drought stress, the proline content reached the maximum when manganese concentration was 0. 8 g·kg^-1, the activity ofδ-OAT and P5CS activity and chlorophyll content reached the peak under 0. 4 g·kg^-1Mn, and the gene expression level of δ-OAT and P5CS reached the maximum when manganese concentration was 0. 2 g·kg^-1. Under normal conditions, changes of chlorophyll and proline contents andδ-OAT activity were similar to those under drought stress. The activi-ty of P5CS reached maximum when manganese concentration was 0. 8 g·kg^-1. The simple, partial correlation and di-rect path coefficients of δ-OAT activity and proline content reached significant level under drought stress, while the simple, partial correlation and direct path coefficients of P5CS activity and proline content reached significant level under normal condition. This study suggested that manganese application amount should be 0. 2-0. 4 g·kg^-1for sug-arcane production in latosol soil, and the stress resistance of sugarcane was strong under this condition. Due to the influences of manganese, the ornithine pathway dominated the proline biosynthesis of sugarcane under drought stress, while the glutamic pathway was dominant under normal water condition.
出处
《浙江农业学报》
CSCD
北大核心
2016年第6期915-921,共7页
Acta Agriculturae Zhejiangensis
基金
广东省科技计划项目(2013B020301005
2013B020301008)
广东省良种培育和引进专项(201201148)
广东海洋大学"强校工程"科研项目(GDOU2015050201)
