水分亏缺对不同抗旱性小麦穗部光呼吸特性及其关键酶基因表达的影响

发布时间：2018-06-27 14:01

本文选题：小麦 + 光呼吸　；参考：《西北农林科技大学》2017年硕士论文

【摘要】：小麦穗部在水分胁迫下具有显著的生理生化优势。光呼吸是植株正常生长不可或缺的代谢途径,对植株的正常生长,尤其是在水分胁迫下有重要作用。本研究采用盆栽试验,选用不同抗旱性小麦品种,测定旗叶和穗部净光合速率、光呼吸速率、产量性状等生理指标及光呼吸关键酶活性和基因表达差异。获得以下主要结果:1.水分亏缺下不同抗旱性小麦西农928、陕229旗叶净光合速率随灌浆进程呈下降趋势,并且对水地品种陕229旗叶花后24d PN影响较大。西农928和陕229穗部PN均呈先增后降趋势。水分亏缺使其灌浆前期(花后6 d)PN分别下降了13.5%和26.4%。表明水分亏缺对两个小麦品种穗部净光合的影响发生在整个灌浆期,水分亏缺对干旱敏感品种小麦穗部光合速率影响更为显著。2.旗叶和穗部Pr随灌浆进程呈先升后降趋势,12d达到峰值。水分亏缺下旱地品种西农928旗叶Pr灌浆后期(花后24d)增幅显著,增加了105.7%(P0.05);而水分敏感品种陕229整个灌浆期增幅较小,灌浆后期(花后24d)下降了23.6%(P0.05)。穗部比旗叶增幅显著,西农928与陕229花后12d分别升高101.97%和90.97%,且两个品种穗部Pr均高于对照。3.旗叶中乙醇酸氧化酶(GO)活性先升后降。旱地品种西农928花后12d GO活性上升了136.8%(P0.05),其余时期也有明显增幅;水分敏感品种陕229花后12d上升57.2%(P0.05)。灌浆期颖壳和外稃中GO活性先升后降。光呼吸与GO活性变化趋势一致。水分亏缺下旗叶GS活性总体均表现为下降趋势。灌浆中期(花后12d)西农928旗叶光呼吸关键酶谷氨酰胺合成酶(GS)活性上升7.51%,陕229则下降16.7%(P0.05)。西农928穗部颖壳GS活性在灌浆后期(花后24d)下降34.2%(P0.05),外稃中GS活性花后24d下降了27.1%(P0.05);陕229分别下降了44.7%和57.8%(P0.05)。GO基因表达量的变化早于GO活性变化,花后3d GO基因表达明显上调,且在西农928中比在陕229中上调明显。而GS基因表达趋势与酶活性结果相近,花后5d下调更明显,表明基因对酶活性起主要作用,基因对水分胁迫的响应比酶活性更早。4.水分亏缺条件下,西农928及陕229的千粒重均显著降低(P0.05),分别为8.14%和11.51%;干旱敏感品种陕229的产量性状和收获指数分别下降了41.4%,16.05%(P0.05),而抗旱品种西农928下降相对较小;水分亏缺下,西农928的WUE降低21.74%(P0.05),而陕229的下降36.02%(P0.05)。
[Abstract]:Under water stress, the panicle of wheat had significant physiological and biochemical advantages. Photorespiration is an indispensable metabolic pathway for the normal growth of plants, which plays an important role in the normal growth of plants, especially under water stress. In this study, pot experiments were conducted to determine the net photosynthetic rate, light respiration rate, yield characters, key enzyme activity and gene expression in flag leaves and panicles of different drought-resistant wheat varieties. Get the following main result: 1. Under the condition of water deficit, the net photosynthetic rate of flag leaves of wheat Xinong 928 and Shan229 decreased with the grain filling process, and had a great effect on PN after 24d of flag leaves in water field variety Shaan 229. PN of panicle of Xinong 928 and Shan 229 increased first and then decreased. The PN in the early stage of grain filling (6 days after anthesis) decreased by 13.5% and 26.4% respectively due to water deficiency. The results showed that the effect of water deficit on the net photosynthesis of panicle of two wheat varieties occurred during the whole filling stage, and the effect of water deficiency on the panicle photosynthetic rate of drought sensitive varieties was more significant. Pr of flag leaf and ear increased first and then decreased to peak at 12 days. Under the condition of water deficit, the increase of pr in flag leaf of Xinong 928 in late filling stage (24 days after anthesis) was significant, which increased by 105.7% (P0.05), while that of water sensitive variety Shaan 229 decreased by 23.6% (P0.05) in late filling stage (24 days after anthesis). The spikes of Xinong 928 and Shan 229 increased by 101.97% and 90.97% respectively 12 days after anthesis, and pr of panicle of both varieties were higher than that of CK. 3. The activity of glycolate oxidase (go) in flag leaves increased first and then decreased. The go activity of dry land variety Xinong 928 increased by 136.8% (P0.05) at 12 days after anthesis, and increased significantly in other periods, while that of water sensitive variety Shaan 229 increased by 57.2% 12 days after anthesis (P0.05). Go activity in glume and Lemma increased first and then decreased at filling stage. The change trend of photorespiration is consistent with that of go activity. The GS activity of flag leaves decreased under water deficit. In the middle filling period (12 days after anthesis), the activity of glutamine synthase (GS), a key enzyme for leaf light respiration of Xinong 928, increased by 7.51%, while Shan229 decreased by 16.7% (P0.05). GS activity in panicle of Xinong 928 decreased by 34.2% (P0.05) at late filling stage (24d after anthesis), decreased by 27.1% (P0.05) at 24d after anthesis in Lemma, and decreased by 44.7% (P0.05) and 57.8% (P0.05) .go gene expression in Shaanxi 229 decreased by 44.7% and 57.8% (P0.05) .Go gene expression increased 3 days after anthesis, respectively. In Xinong 928, it was obviously up-regulated than in Shan 229. The expression trend of GS gene was similar to that of enzyme activity, and the down-regulation of GS gene was more obvious at 5 days after anthesis, indicating that the gene played a major role in enzyme activity, and the response of GS gene to water stress was earlier than that of enzyme activity. Under the condition of water deficit, the 1000-grain weight of Xinong 928 and Shan 229 decreased significantly (P0.05), which were 8.14% and 11.51%, respectively, and the yield characters and harvest index of drought sensitive cultivar Shaan229 decreased by 41.4% (P0.05), while that of drought-resistant variety Xinong 928 decreased relatively slightly. The Wue of Xinong 928 was decreased by 21.74% (P0.05), while that of Shaan 229 was decreased by 36.02% (P0.05).
【学位授予单位】：西北农林科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S512.1

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