Growth characteristics and endosperm structure of superior and inferior spikelets of indica rice under high-temperature stress
Growth characteristics and endosperm structure of superior and inferior spikelets of indica rice under high-temperature stress
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DOI：
10.1007/s10535-016-0606-6
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发表时间：
2016-09-01
影响因子：
1.5
通讯作者：
Zhang, J. H.
中科院分区：
文献类型：
--
作者：
Cao, Y. Y.;Chen, Y. H.;Zhang, J. H.
高温胁迫严重降低了水稻产量和品质，然而，早花籼稻的上级颖花和晚花籼稻的弱势颖花对灌浆期高温胁迫的反应差异尚不清楚。研究了高温（33.6/20.7 A ℃昼/夜）对籼型耐热和热敏品种（SG-1和HHZ）的上级和弱势颖花生长、胚乳结构、激素和多胺含量的影响。高温处理降低了受精率，使籽粒灌浆提前，灌浆持续时间缩短，从而导致籽粒质量下降，胚乳结构不良。此外，高温处理使灌浆前期可溶性糖和蔗糖含量增加，淀粉合成减少。高温处理提高了籽粒中多胺[亚精胺（Spd）和精胺（Spm）]和脱落酸（阿坝）的含量，降低了玉米素（Z）+玉米素核苷（ZR）和吲哚乙酸（IAA）的含量。这种效应在下位小穗中比在上级小穗中更明显，而SG-1的下位小穗比HHZ的下位小穗受影响更大。在灌浆中期，HT在两个品种间差异不大。我们的研究结果表明，SG-1的弱势小穗在高温下的不良发展，可以归因于，至少部分地，在自由多胺[腐胺（Put），Spd，Spm]和植物激素（Z+ZR，IAA，阿坝）的含量和比例的变化和蔗糖转化为淀粉的效率。
Heat stress severely reduces rice yield and quality; however, differences between the superior, early-flowering and inferior, later-flowering spikelets of indica rice in response to high-temperature stress during grain filling remain unclear. This study investigated the effects of high temperature (HT, 33.6/20.7 A degrees C day/night) on growth, endosperm structure, and hormone and polyamine content of superior and inferior spikelets of heat-sensitive (SG-1) and heat-tolerant (HHZ) indica cultivars. The HT decreased fertilization rate, caused earlier grain filling, and reduced duration of grain filling, thus resulting in decreased grain mass and a poor endosperm structure. In addition, soluble sugar and sucrose content increased, and starch synthesis decreased by HT at the early stage of grain filling. The HT increased polyamine [spermidine (Spd) and spermine (Spm)] and abscisic acid (ABA) content, but reduced zeatin (Z) + zeatin riboside (ZR) and indole-3-acetic acid (IAA) content in the grains. Such effects were more apparent in the inferior than superior spikelets; however, the inferior spikelets of SG-1 were more affected than those of HHZ. At the middle grain filling stage, HT produced little difference between the two cultivars. Our results suggest that the poor development of inferior spikelets of SG-1 under the HT could be attributed, at least in part, to the changed content and ratios of free polyamines [putrescine (Put), Spd, and Spm] and phytohormones (Z+ZR, IAA, and ABA) and the conversion efficiency of sucrose into starch.