中国农业科学 ›› 2018, Vol. 51 ›› Issue (11): 2060-2071.doi: 10.3864/j.issn.0578-1752.2018.11.004

• 耕作栽培·生理生化·农业信息技术 • 上一篇    下一篇

小麦根中NADP-脱氢酶系统关键酶活性与根系活力和产量的关系分析

周燕1,杨习文1,周苏玫1,王言景2,杨蕊1,徐凤丹1,梅晶晶1,申冠宇1,李秋杰1,贺德先1

 
  

  1. 1河南农业大学农学院/河南粮食作物协同创新中心/省部共建小麦玉米作物学国家重点实验室,郑州 450002;2郑州师范学院,郑州 450002
  • 收稿日期:2017-11-03 出版日期:2018-06-01 发布日期:2018-06-01
  • 通讯作者: 贺德先,E-mail:hedexian@126.com
  • 作者简介:周燕,E-mail:yanzhouing@126.com
  • 基金资助:
    科技部“十二五”国家科技支撑计划(2013BAD07B07-4)

Activities of Key Enzymes in Root NADP-Dehydrogenase System and Their Relationships with Root Vigor and Grain Yield Formation in Wheat

ZHOU Yan1, YANG XiWen1, ZHOU SuMei1, WANG YanJing2, YANG Rui1, XU FengDan1, MEI JingJing1, SHEN GuanYu1, LI QiuJie1, HE DeXian1   

  1. 1College of Agronomy, Henan Agricultural University/Collaborative Innovation Center of Henan Grain Crops/State Key Laboratory of Wheat and Maize Crop Science, Zhengzhou 450002; 2Zhengzhou Normal University, Zhengzhou 450002
  • Received:2017-11-03 Online:2018-06-01 Published:2018-06-01

摘要: 【目的】在黄淮平原典型农田氮肥减施条件下,探索决定小麦根系活力的关键脱氢酶种类及酶活性变化及其对籽粒产量的影响。【方法】采用大田试验方式,运用裂区设计,主处理为施氮量,设0(N0),135(N1),157.5(N2),180(N3),202.5(N4),225(N5)kg·hm-2 6个施氮水平,副处理为半冬性品种矮抗58和周麦27号。对小麦越冬期、返青期、拔节期、挑旗抽穗期、灌浆期和蜡熟期根中异柠檬酸脱氢酶(NADP-ICDH)、NADP-苹果酸酶(NADP-ME)、戊糖磷酸途径总脱氢酶(G6PDH+6PGDH)活性与根系活力(改良TTC法)和产量间的关系进行分析。【结果】小麦关键生育时期根系活力呈“高-低-高-低”变化,NADP-ICDH,NADP-ME和(G6PDH+6PGDH)活性变化均表现为先上升后下降的趋势,灌浆后活性变化不明显。越冬前后,不同施氮处理间根中NADP-脱氢酶系统关键酶活性表现为不施氮处理(N0)大于施氮处理(N1—N5);拔节—抽穗期,NADP-脱氢酶系统关键酶活性和根系活力均表现为施氮处理(N1—N5)显著高于不施氮(N0)处理,随着施氮水平逐步降低不同酶活性随之降低,与N5处理相比,N4处理NADP-ICDH和NADP-ME的活性未达显著水平,同时(G6PDH+ 6PGDH)活性和根系活力降幅最少。施氮量显著影响小麦籽粒产量及其构成因素,与不施氮处理(N0)相比,施氮处理(N1—N5)下的单位面积成穗数、穗粒数显著提高。综合两年度产量平均值可知,N5处理下籽粒产量最高,达9 238.02 kg·hm-2N4处理次之,较N5处理仅下降0.3%且差异未达显著水平。进一步分析表明,不同生育时期根中NADP-ICDH、NADP-ME与(G6PDH+6PGDH)三者之间呈显著或极显著正相关关系;NADP-脱氢酶系统关键酶活性与根系活力呈正相关关系,其中生育中、后期达显著或极显著水平;根系活力及NADP-ICDH,NADP-ME和(G6PDH+6PGDH)活性与产量呈显著或极显著正相关关系。通径分析表明,两年度NADP-ICDH,NADP-ME和(G6PDH+6PGDH)活性在拔节期和挑旗抽穗期对产量有较大的正向作用;挑旗抽穗期根系活力对产量的直接作用较小,但其通过NADP-ME和戊糖磷酸途径总脱氢酶(G6PDH+6PGDH)活性对产量所产生的间接正向作用较大,因而根系活力对产量的影响达极显著水平。【结论】本试验条件下,综合考虑NADP-脱氢酶系统关键酶活性和根系活力变化及籽粒产量表现,黄淮平原麦田施氮水平由N5减至N4水平当是最佳选择NADP-ICDHNADP-ME和(G6PDH+6PGDH)活性与采用改良TTC法测定的“根系活力”密切相关,其中NADP-ME和(G6PDH+6PGDH)活性对根系活力影响最大,实践中可通过分子育种手段和有效栽培措施实现NADP-ME和(G6PDH+6PGDH)在根中的高表达以提高小麦根系活力

关键词: 小麦, 异柠檬酸脱氢酶, NADP-苹果酸酶, 戊糖磷酸途径总脱氢酶, 根系活力(改良TTC法), 产量

Abstract: 【Objective】Field experiments were conducted to explore activities of key enzymes in wheat (Triticum aestivum L.) root NADP-dehydrogenase system and their relationships with root vigor and grain yield under the condition of reducing nitrogen fertilization in the typical field on the Huang-Huai Plain, in China.【Method】A split block design was employed with 2 semi-winterness wheat cultivars, Aikang 58 and Zhoumai 27, and 6 nitrogen fertilizer application rates: 0 (N0), 135 (N1), 157.5 (N2), 180 (N3), 202.5 (N4), and 225 kg N·hm-2 (N5). Activities of NADP-ICDH, NADP-ME and (G6PDH+6PGDH) and root vigor by improved TTC method were measured prior to wintering, and at re-growing, jointing, heading, grain filling and late dough stage. And then, the relationships between activities of these key enzymes with root vigor at different growth stages and grain yield were analyzed.【Result】The results showed that dynamics of root vigor had a “high-low-high-low” trend during the whole wheat growing period. Activities of NADP-ICDH, NADP-ME and (G6PDH+6PGDH) were all increased at first and then decreased. However, difference in activities of these key enzymes was not significant at 5% probability level after grain-filling stage. Before jointing stage, activities of key enzymes in the NADP-dehydrogenase system were greater in N0 than those in nitrogen application treatments N1-N5. However, from jointing to heading stage, activities of key enzymes and root vigor under the treatments from N1 to N5 were significantly higher than that under N0. Further analysis pointed out that both activity of NADP-dehydrogenases and root vigor were decreased with the decrease of nitrogen fertilization rate. Compared with N5, decrease both in activities of NADP-ICDH, NADP-ME and (G6PDH+6PGDH), and in root vigor under N4 were the least. Nitrogen application rate significantly affected wheat grain yield and its components. Compared with N0, wheat spikes per unit area and grains per spike were significantly increased under nitrogen treatments N1-N5. Average grain yield in 2 experimental years indicated that yield under N5 was the highest, 9 238.02 kg·hm-2. Compared with N5, the wheat grain yield under N4 was only decreased by 0.3% while those under treatments of N3-N0 were decreased significantly. Statistical analyses showed that there were significant or extremely significant positive correlations between activities of NADP-ICDH, NADP-ME, and (G6PDH+6PGDH) at different growth stages. And there were significant or extremely significant positive correlations between activities of key enzymes in root NADP-dehydrogenase system with root vigor in middle and late wheat growing period. Grain yield had significant or extremely significant positive correlations with root vigor, activities of NADP-ICDH, NADP-ME, and (G6PDH+6PGDH). Path analysis further showed that activities of NADP-ICDH, NADP-ME and (G6PDH+6PGDH) at both jointing and heading stages had greater positive effects on grain yield in two years. Direct effects of root vigor at heading stage on yield were smaller, however, indirect positive effects of root vigor by means of increase in activities of NADP-ME and (G6PDH+6PGDH) on grain yield were significant or extremely significant.【Conclusion】Under the experimental conditions in this study, reducing nitrogen application rate from N5 to N4 could be optimum at present in wheat field in the Huang-Huai Plain, considering dynamics of activities of key enzymes in root NADP-dehydrogenase system, root vigor and grain yield. NADP-ICDH, NADP-ME and (G6PDH+6PGDH) were closely related to the "root vigor" determined by the improved TTC method. Particularly, NADP-ME and (G6PDH+6PGDH) were the most important enzymes. It was concluded that wheat root vigor could be improved by high expression of NADP-ME and (G6PDH+6PGDH) in roots, which could be achieved by means of molecular breeding and effective cultivation operations.

Key words:  wheat, isocitric dehydrogenase, NADP-malate dehydrogenase; total dehydrogenases of pentose phosphate pathway, root vigor (by improved TTC method), grain yield