一氧化氮参与钾胁迫对烟草根系生长的影响
毕业论文关键字：延伸次根 NO 钾缺乏烟草
目录
摘要1
关键词1
Abstract1
Key words1
1.简介1
2.材料和测定方法2
2.2.1植物生长3
2.2.2根系结构记录4
2.2.3钾浓度测定4
2.2.4根尖NO含量的测定4
2.2.5硝酸还原酶（NR）活性测定4
2.2.6 qRT-PCR分析4
2.2.7数据分析5
3.结果5
3.3.1两个品种烟草对钾缺乏的反应的不同5
3.3.2缺钾抑制云烟一号的一级侧根的生长和延长7
3.3.3缺钾使云烟1号中NO含量增加，而NC89则不增加7
3.3.4低钾情况下通过硝酸还原酶途径诱导NO含量增加8
3.3.5外源添加NO供体和NO清除剂影响一级侧根伸长9
3.3.6生长素介导产生的NO也可以在缺钾下抑制一级侧根伸长10
4.讨论11
5.参考文献12
一氧化氮参与钾胁迫对烟草根系生长影响
Abstract：Potassium (K+) is a major limiting element of plant growth, and crops often suffer from low-K+ (LK) stress. Although nitric oxide (NO) is a signaling molecule involved in plant root adaptation to the environment, it remains unclear whether it participates root growth regulated by LK conditions. Two tobacco cultivars (Nicotiana tabacum L.) exhibiting variant growth features under LK were used in this study. We investigate the effects of LK on root growth, NO-accumulation, nitrate-reductase (NR) activity and effects of NO-donor (SNP), NO-scavenger (cPTIO), NR-inhibitor (tungstate), and NO-synthase-inhibitor (L-NAME) on elongation of first-order lateral-root (LR). Compared with control-treatment, LK-tolerant cultivar NC89 maintained plant growth under LK at 14 days, while dry weight was reduced significantly in LK-susceptible cultivar Yunyan1. Low-K+-inhibited root growth, mostly by impairing first-order LR’sformation and elongation, was only recorded in cv. Yunyan1. NO accumulation increased in root tips even when cv. Yunyan1 subjected to LK at day 1. LK-induced NO was generated by NR-pathway during early LK. SNP-application to control-treated plants decreased first-order LR elongation to levels similar to LK-treatment in cv. Yunyan1, while cPTIO, L-NAME, and application had the opposite effect. Further results suggested that NO might be involved in auxin-mediated LR elongating as plants responding to LK. In conclusion, NO generated by NR pathway may be involved in the inhibition by LK-stress of first-order LR elongation in tobacco plants.
Key words:elongation;LR;NO;LK;tobacco
1. 简介
钾离子是植物生长发育中一种必需营养物质。可以占到植物干重的10%以上，而且是植物细胞中最重要的阳离子。然而，土壤中的钾离子浓度在0.025–5.0 mM，但是在根际中，浓度一般小于0.3 m[1]。即使在肥沃的土壤中，钾离子的可利用性也和环境条件有关，比如说土壤湿度和土壤密度[2]。所以说。植物可能经常性经历钾离子缺乏的情况。
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