Water stress during grain development affects starch synthesis, composition and physicochemical properties in triticale
Water stress during grain development affects starch synthesis, composition and physicochemical properties in triticale
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DOI：
10.1016/j.jcs.2012.07.011
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发表时间：
2012-11-01
影响因子：
3.8
通讯作者：
Lu, Zhen-Xiang
中科院分区：
文献类型：
--
作者：
He, Jiang-Feng;Goyal, Ravinder;Lu, Zhen-Xiang
黑小麦是由小麦和黑麦杂交而成的一种人造谷类作物，具有优良的农艺性状，可以生产用于生物工业应用的淀粉。研究了不同程度水分胁迫对玉米淀粉合成基因表达、淀粉组成和理化性质的影响。以3个小黑麦品种为试材，从花后5d开始进行3种不同程度的水分胁迫处理：低水分胁迫（土壤含水量55-60%）、中度水分胁迫（土壤含水量30-35%）和重度水分胁迫（土壤含水量10-15%）。水分胁迫导致种子重量在SWS下显著降低（35-45%）。从MWS开始，淀粉含量明显降低，所有品种在SWS时的值降低了42-55%。这种下降与水分胁迫（DWS）19天时淀粉合成基因的表达减少有关。MWS有利于增加小黑麦淀粉中直链淀粉的比例，并伴随着在整个籽粒发育过程中GBSSI表达的显著上调。水分胁迫下小黑麦淀粉合成的小颗粒数量减少，A型淀粉与B型淀粉的比例增加。SWS引起淀粉颗粒上的点蚀，但没有改变成熟颗粒的双凹盘形状。水分胁迫和淀粉糊化温度的范围之间的反比关系进行了观察和MWS环境具体降低峰值温度（Tp）和增加焓。研究结果表明，干旱条件下小黑麦籽粒淀粉的形态、组成和理化性质发生了变化。皇冠版权所有（C）2012由爱思唯尔有限公司出版。保留所有权利。
Triticale, a man-made cereal crop developed from a cross between wheat and rye, has excellent agronomic traits to produce starch for bioindustrial applications. The effects of different levels of water stress on expression of starch synthesis genes and starch composition and physicochemical properties were investigated in this study. Three triticale varieties from 5 days post-anthesis were treated with three levels of water stress: low water stress (LWS) at 55-60% of soil moisture, moderate water stress (MWS) at 30-35% soil moisture and severe water stress (SWS) at 10-15% soil moisture. Water stress led to a significant reduction in seed weight at SWS (35-45%). A decrease in starch content was noticeable from MWS onwards and the values were decreased by 42-55% at SWS across all varieties. Such decrease was associated with the reduced expression of starch synthesis genes at 19 days of water stress (DWS). MWS favoured an increase of amylose proportion in triticale starch and it was accompanied by a significant up-regulation of GBSSI expression throughout the grain development. Triticale starch synthesized under water stress showed a reduced population of small granules and an increase of A-type to B-type ratio. SWS caused pitting on starch granules but did not alter the biconcave disc shape of mature granules. An inverse relationship between water stress and a range of starch gelatinization temperature was observed and the MWS environment specifically decreased the peak temperature (Tp) and increased the enthalpy. Our results signify that starch morphology, composition and physicochemical properties in triticale grains could be altered if triticale is grown under drought conditions. Crown Copyright (C) 2012 Published by Elsevier Ltd. All rights reserved.