中国农业科学 ›› 2021, Vol. 54 ›› Issue (9): 1821-1834.doi: 10.3864/j.issn.0578-1752.2021.09.001

• 作物遗传育种·种质资源·分子遗传学 • 上一篇    下一篇

花后DA-6处理调控小麦种子活力的机理

许晨(),王文静,曹珊,李如雪,张贝贝,孙爱清(),张春庆()   

  1. 山东农业大学农学院/作物生物学国家重点实验室/山东省作物生物学重点实验室,山东泰安 271018
  • 收稿日期:2020-08-24 接受日期:2020-10-19 出版日期:2021-05-01 发布日期:2021-05-10
  • 通讯作者: 孙爱清,张春庆
  • 作者简介:许晨,E-mail:xuchen0905@foxmail.com
  • 基金资助:
    国家重点研发计划七大农作物育种专项课题(2018YFD0100904)

Mechanism of DA-6 Treatment Regulating Wheat Seed Vigor After Anthesis

XU Chen(),WANG WenJing,CAO Shan,LI RuXue,ZHANG BeiBei,SUN AiQing(),ZHANG ChunQing()   

  1. College of Agriculture, Shandong Agricultural University/State Key Laboratory of Crop Biology/Shandong Key Laboratory of Crop Biology, Tai’an 271018, Shandong
  • Received:2020-08-24 Accepted:2020-10-19 Online:2021-05-01 Published:2021-05-10
  • Contact: AiQing SUN,ChunQing ZHANG

摘要:

【背景】高活力的种子萌发迅速整齐,抗逆性强,具有很大的生产优势。己酸二乙氨基乙醇酯(DA-6)作为叔胺类植物生长调节剂,可以提高植物的光合速率,调节碳氮代谢,提高作物品质和产量。【目的】分析花后喷施DA-6对小麦籽粒物质积累、物质代谢和抗逆关键基因表达、种子千粒重、化学成分与种子活力的影响,明确DA-6调控小麦种子活力的机理,为DA-6在小麦高活力种子生产调控中的应用提供理论依据和技术支持。【方法】以小麦品种良星77和山农23号为材料,于花后2和6 d进行DA-6田间喷施。试验于2017—2018年、2018—2019年在山东农业大学马庄试验基地(117°E;36°N)进行,设置2个处理浓度(0和6 g·L-1 DA-6)和2个处理时期(花后2和6 d),设置3个区组,每个小区面积6 m×3 m。于籽粒灌浆前期和中期(花后12和22 d)取籽粒、穗下节和旗叶鲜样,用于物质代谢关键酶基因表达的检测。于籽粒发育的不同天数取样(花后25、30、35和40 d),自然晒干后脱粒测定千粒重和蛋白质含量、淀粉含量等;对于成熟期收获的小麦穗,取小麦整穗、不同穗位(上部、中部和下部)、不同粒位(下位粒和上位粒)的种子测定发芽活力指标。【结果】花后6 d喷施6 g·L-1DA-6可大幅度提高千粒重及种子蛋白质含量,使2个小麦品种的穗上部和上位粒种子的单株干重显著增加,显著提高种子的活力指数。花后6 d喷施DA-6有效降低了不同穗粒位之间的种子活力差异,使小麦不同穗位、粒位种子的活力得到整体提高,尤其以穗上中部籽粒及上位粒的种子活力提高更为明显。而花后2 d喷施DA-6则使种子活力显著降低,千粒重及种子蛋白质含量也有降低。良星77和山农23号的千粒重均表现为随着籽粒灌浆期的延长,千粒重先升高后降低;但相对蛋白及绝对蛋白含量则表现为随着时间的延长而渐升。同时,两品种均表现为花后6 d喷施6 g·L-1的DA-6时千粒重及蛋白质含量最高。此处理下,良星77花后40 d收获时,千粒重与对照相比无显著差异,但相对蛋白质含量、绝对蛋白质含量分别较对照显著提高;山农23号花后6 d喷施6 g·L-1 DA-6后千粒重、绝对蛋白含量均显著提高。两品种花后2 d喷施DA-6对千粒重、相对蛋白质含量、绝对蛋白含量及淀粉含量无显著影响。实时荧光定量PCR表明,花后6 d喷施DA-6可诱导叶片蛋白磷酸酶和蔗糖磷酸合成酶基因表达水平显著上调,茎秆中Ⅰ类hsphsp70表达量显著提高,籽粒中蛋白质二硫键异构酶和hsp82的表达也显著上调。花后6 d喷施DA-6处理的小麦种子萌发期α-淀粉酶活性检测表明,山农23号的对照和处理组均表现为其α-淀粉酶活性随着萌发时间的延长逐渐增强,喷施DA-6可显著提高2个品种的种子萌发72 h的α-淀粉酶活性。【结论】花后6 d喷施DA-6促进小麦中蛋白和蔗糖代谢关键酶基因及热激蛋白基因的表达,有利于促进种子贮藏物质合成,使种子蛋白质含量升高,最终导致千粒重提高;同时还显著增加2个小麦品种穗上中部及上位粒种子萌发过程中的单株干重,提高种子的活力指数,降低不同穗粒位之间种子活力的差异,提高种子萌发过程中的α-淀粉酶活性和物质转化能力,促进幼苗干物质积累,最终提高种子活力。小麦种子花后6 d喷施6 g·L-1 DA-6是提高小麦种子活力的有效途径。

关键词: 小麦, 己酸二乙氨基乙醇酯, 种子活力, 实时荧光定量PCR

Abstract:

【Background】High-vigor seeds germinate quickly and efficiently, and they are highly stress resistant and advantageous during crop production. Diethyl aminoethyl hexanoate (DA-6), as a tertiary amine plant growth regulator, increases plant photosynthetic rates, regulates carbon and nitrogen metabolism and improves crop quality and yield. However, there are limited studies on its effects on seed vigor. 【Objective】This study analyzed the effects of spraying DA-6 post-flowering on the compounds accumulated in grains, expression levels of key genes associated with metabolism and stress-resistance, 1000-grain weights, chemical compositions and seed vigor to determine DA-6’s mechanism for regulating wheat seed vigor, which has important theoretical and practical significance in the production of high-vigor wheat seeds. 【Method】Wheat varieties, Liangxing 77 and Shannong 23, grown in fields of the Mazhuang Experimental Base of Shandong Agricultural University in 2017-2018 and 2018-2019 (117°E, 36°N) were sprayed with DA-6. Two treatment concentrations (0 and 6 g·L-1 DA-6), two treatment periods (2 and 6 days after anthesis) and three zone groups, each having an area of 6 m × 3 m, were used. Fresh samples of grains, stems below spikes and flag leaves were collected at the early and middle stages of grain filling (12 and 22 days after anthesis, respectively), and the expression levels of key metabolism-related enzymes were analyzed. Samples were taken on different days of grain development (25, 30, 35 and 40 days after anthesis), and the 1000-grain weights, protein contents and starch contents were determined after natural drying and threshing. For wheat spikes harvested at the maturity stage, the germination and vigor indices of the whole ear, different spike positions (upper, middle and lower) and different grain positions (lower and upper grain) were measured. 【Result】Spraying 6 g·L-1 DA-6 at 6 days after anthesis significantly increased the 1000-grain weights, seed protein contents, and plant dry weights of the upper spikes and upper grains in both wheat varieties, and it significantly improved the seed vigor indices. DA-6 spraying at 6 days after anthesis effectively reduced the seed vigor difference between different spike and grain positions, and it improved the seed vigor of different spike and grain positions in wheat as a whole, especially those of upper and middle spikes, as well as the upper grain. However, DA-6 spraying at 2 days after anthesis significantly reduced seed vigor, 1000-grain weights and seed protein contents. The 1000-grain weights of Liangxing 77 and Shannong 23 increased first and then decreased as the grain-filling period was extended. However, relative and absolute protein contents increased with time. Additionally, both varieties showed the highest 1000-grain weights and protein contents after spraying 6 g·L-1 DA-6 at 6 days after anthesis. While the 1000-grain weight of Liangxing 77 was not significantly different from that of the control group, the relative and absolute protein contents were significantly greater. The 1000-grain weight and absolute protein content of Shannong 23 significantly increased after spraying 6 g·L-1 DA-6 at 6 days after anthesis. DA-6 spraying at 2 days after anthesis had no significant effects on 1000-grain weights, relative and absolute protein contents or starch contents. Real fluorescence quantitative PCR showed that DA-6 spraying at 6 days after anthesis significantly increased the expression levels of protein phosphatase and sucrose phosphate synthase in flag leaves. The expression levels of class I heat shock protein (hsp) and hsp70 in the stem, like those of protein disulfide isomerase and hsp82 in grains, increased significantly. The α-amylase activity during seed germination was measured in samples sprayed with DA-6 at 6 days after anthesis. The activity gradually increased along with germination time in both control and treated Shannong 23. DA-6 spraying at 6 days after anthesis significantly increased the α-amylase activity levels in seeds of both varieties after germinating for 72 h. 【Conclusion】Spraying DA-6 at 6 days after anthesis promoted the expression levels of proteins, key enzyme-encoding genes of sucrose metabolism and hsps. It also facilitated the synthesis of seed storage substances, increased the protein contents of seeds and significantly increased the 1000-grain weights. The dry weight of individual plants during germination and seed vigor of upper, middle spikes and the upper grain of harvested seeds in two varieties significantly improved after spraying DA-6. The seed vigor difference between different spike positions decreased, and the α-amylase activity increased during seed germination. Thus, spraying DA-6 after anthesis promoted the accumulation of seedling dry matter and improved material transformation capacities during seed germination. Additionally, seed vigor improved. Our studies suggest that spraying 6 g·L-1 DA-6 on wheat at 6 days after anthesis is an effective way to improve seed vigor.

Key words: wheat, DA-6, seed vigor, real-time PCR