中国农业科学 ›› 2015, Vol. 48 ›› Issue (7): 1288-1299.doi: 10.3864/j.issn.0578-1752.2015.07.04

• 耕作栽培·生理生化 • 上一篇    下一篇

花后轻干-湿交替灌溉提高水稻籽粒淀粉合成相关基因的表达

陈婷婷1,2,许更文1,钱希旸1,王志琴1,张耗1,杨建昌1   

  1. 1扬州大学江苏省作物遗传生理国家重点实验室培育点/粮食作物现代产业技术协同创新中心,江苏扬州225009
    2中国水稻研究所/水稻生物学国家重点实验室,杭州 310006
  • 收稿日期:2014-04-25 出版日期:2015-04-01 发布日期:2015-04-01
  • 通讯作者: 杨建昌,Tel:0514-87979317;E-mail:jcyang@yzu.edu.cn
  • 作者简介:陈婷婷,Tel:0571-63370370;E-mail:ntchtt@163.com
  • 基金资助:
    国家自然科学基金(31461143015,31271641,31071360,31471438)、国家“863”计划项目(2014AA10A605)、国家公益性行业(农业)科研专项(201103003,201203079,201203029)、国家“十二五”科技支撑计划项目(2011BAD16B14,2012BAD04B08,2013BAD07B09)、江苏省农业三新工程项目(SXG2014313)、江苏高校优势学科建设工程专项、中央级公益性科研院所基本科研业务费专项项目(2014RG004-4)

Post-Anthesis Alternate Wetting and Moderate Soil Drying Irrigation Enhance Gene Expressions of Enzymes Involved in Starch Synthesis in Rice Grains

CHEN Ting-ting1,2, XU Geng-wen1, QIAN Xi-yang1, WANG Zhi-qin1, ZHANG Hao1, YANG Jian-chang1   

  1. 1Jiangsu Key Laboratory of Crop Genetics and Physiology, Yangzhou University /Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou 225009, Jiangsu
    2China National Rice Research Institute/State Key Laboratory of Rice Biology, Hangzhou 310006
  • Received:2014-04-25 Online:2015-04-01 Published:2015-04-01

摘要: 【目的】水稻籽粒灌浆是光合同化产物向籽粒运输并合成淀粉的生理过程,决定水稻结实率、粒重高低及品质优劣。籽粒灌浆过程不仅受遗传因素的影响,而且受到温度和水分等环境因子的调节。灌溉是水稻生产上一项重要的技术,对水稻产量的形成有重要调控作用。但有关花后灌溉方式对水稻籽粒淀粉合成相关基因表达的影响,缺乏研究。本研究旨在探讨花后干湿交替灌溉对水稻籽粒灌浆的影响并阐明其分子机理。【方法】2012—2013年以两优培九(两系杂交籼稻)和扬粳4038(杂交粳稻)为材料种植于土培池,自抽穗(50%穗伸出剑叶叶鞘)至成熟设置3种灌溉方式处理:(1)常规灌溉(conventional irrigation,CI),保持浅水层,收获前一周断水;(2)轻干-湿交替灌溉(alternate wetting and moderate soil drying,WMD),自浅水层自然落干至土壤水势达-20 kPa时,灌水1—2 cm,再自然落干至土壤水势为-20 kPa,再上浅层水,如此循环;(3)重干-湿交替灌溉(alternate wetting and severe soil drying,WSD),自浅水层自然落干至土壤水势达-40 kPa时,灌水1—2 cm,再自然落干至土壤水势为-40 kPa,再上浅层水,如此循环。观察花后干湿交替灌溉对水稻强、弱势粒灌浆速率、粒重和淀粉合成相关酶活性的影响,并应用实时荧光定量PCR技术测定编码这些酶基因的相对表达量。【结果】强势粒的平均灌浆速率、粒重、淀粉合成有关的蔗糖合酶(SuS)、腺苷二磷酸葡萄糖焦磷酸化酶(AGP)、淀粉合酶(StS)和淀粉分支酶(SBE)等相关酶活性以及蔗糖合酶基因SuS2SuS4,腺苷二磷酸葡萄糖焦磷酸化酶基因AGPL1AGPL2AGPL3AGPS2,淀粉合酶基因SSISSIIaSSIIcSSIIIa和淀粉分支酶基因SBEISBEIIb的相对表达量在3种灌溉方式处理间没有显著差异。与常规灌溉相比,轻干-湿交替灌溉处理显著增加了弱势粒的平均灌浆速率、粒重、4种籽粒淀粉合成相关酶活性和除AGPL1外各基因的相对表达量,重干-湿交替灌溉处理则显著降低弱势粒的平均灌浆速率、粒重、各淀粉合成相关酶活性和基因的相对表达量。两供试品种试验结果趋势一致。相关分析表明,弱势粒的平均灌浆速率、粒重与SuS、AGP、StS、SBE活性以及SuS2SuS4AGPL2AGPL3AGPS2SSISSIIaSSIIcSSIIIaSBEISBEIIb基因的相对表达量呈极显著正相关关系。【结论】在轻干-湿交替灌溉处理下,水稻弱势粒淀粉合成相关酶活性及其基因表达的增强促进了弱势粒中淀粉的合成与积累,提高灌浆速率和增加粒重;而在重干-湿交替灌溉处理下,弱势粒中上述淀粉合成相关酶活性和基因表达的下降使其灌浆速率和粒重显著降低。

关键词: 水稻, 干湿交替灌溉, 强/弱势粒, 籽粒灌浆, 淀粉合成相关酶, 基因表达

Abstract: 【Objective】Grain filling in rice is a physiological process of transportation and conversion of photosynthetic assimilates into starch which determines the percentage of filled grains, grain weight, and rice quality. The process of grain filling could not only be affected by genetic factors, but also be regulated by environmental conditions such as temperature and moisture. Irrigation is an important technique in rice production and plays a vital role in regulating the formation of grain yield. However, little work has been done in the effect of postanthesis irrigation patterns on the expressions of genes encoding starch biosynthesis in rice grains. This study aims to investigate the effect of post-anthesis alternate wetting and drying irrigation on grain filling of rice and to understand its molecular mechanism.【Method】Two cultivars Liangyoupeijiu (two-line indica hybrids) and Yangjing 4038 (japonica hybrids) were used and grown in the cement tanks that were filled with soil. Three irrigation regimes were imposed from heading (50% of the panicles were protrudent the flag leaf sheath) to maturity: (1) conventional irrigation (CI), plots were kept a continuous shallow water layer until one week before harvest; (2) alternate wetting and moderate soil drying irrigation (WMD), the field was not irrigated until the soil water potential reached the threshold at -20 kPa, and then was flooded with 1-2 cm water depth, and was repeated this process again; (3) alternate wetting and severe soil drying irrigation (WSD), water in the plots was withheld until the soil water potential reached the threshold at -40 kPa, and then was flooded with 1-2 cm water depth, and this process was repeated again. The effect of irrigation regimes on grain filling rate, grain weight, activities of the enzymes involved in starch synthesis in superior and inferior spikelets, and expressions of the genes encoding these enzymes were determined using real-time quantitative PCR.【Result】The results showed that there were no significant differences in grain filling rate, grain weight, activities of enzymes involved in starch synthesis including sucrose synthase (SuS), adenosine diphosphate glucose pyrophosphorylase (AGP), starch synthase (StS), starch branching enzyme (SBE) and SuS2, SuS4, AGPL1, AGPL2, AGPL3, AGPS2, SSI, SSIIa, SSIIc, SSIIIa, SBEI and SBEIIb gene expressions in superior spikelets among the three irrigation treatments. Compared with CI, the WMD significantly increased the mean grain filling rate, grain weight, activities of the four enzymes involved in starch synthesis and their gene expressions in inferior spikelets except for AGPL1, whereas the WSD performed an opposite effect. The two trial cultivars behaved the same tendency. The correlation analysis showed that the mean grain filling rate and the grain weight of inferior spikelets were very significantly and positively correlated with activities of SuS, AGP, StS, SBE and gene expressions of SuS2, SuS4, AGPL2, AGPL3, AGPS2, SSI, SSIIa, SSIIc, SSIIIa, SBEI and SBEIIb. 【Conclusion】The results indicate that enhanced activities and gene expressions of the enzymes involved in starch synthesis in inferior spikelets under WMD contribute to their greater grain filling rate and grain weight through enhancing the starch synthesis and accumulation. The reduction in the grain filling rate and grain weight of inferior spikelets under WSD would be attributed to the decreased activities and gene expressions of the enzymes involved in starch synthesis.

Key words: rice, alternate wetting and drying irrigation, superior/inferior spikelets, grain filling, enzymes involved in starch synthesis, gene expression