气温升高和干旱胁迫对灵武长枣果实糖分积累和着色的影响机理

Climate change caused by elevated CO2 concentration shows great impact on agricultural and forestry ecosystem, so the response of plant growth and developent to elevated temperature and drought stress hvae been paied great attention. But there is few reports about the effect of elevated temperature and drought stress on fruit quality formation of woody plants, because the response varied with the species of the plants. On the basis of the preliminary study, taking Zizyphus jujuba Mill. cv. Lingwu changzao, a characteristic variety of no-wood production forest in Ningxia, as materials, we will apply improved opent-top-chambers to simulate the controlling elevated temperature environment, aoutmatic water-saving irrigation system to control soil moisture levels, and test the content variations of soluble sugar, fructose, sucrose, etc., and the enzymes activity related to glycometabolism in fruit and leaf of the jujube planted under elevated temperature and soil drought stress conditiont, then analyze the sugar accumulation characteristics. We also test the chlorophyll content， carotenoid content，anthocyanin content and the enzymes activity related to its metabolism, and identified the differential expression genes of enzymes related to glycometabolis with transcriptome sequencing technique.All these will clarify the effect mechanism of elevated temperature and soil drought stress on glycometabolism and fruit coloring in Zizyphus jujuba Mill. cv. Lingwu changzao at a molecular level, and discover the effect mechanism of climate change on fruit quality formation of woody plants, which will propose some theoretical and scientific references to cultivation and breeding of nontimber product forest.

全球气候变化对农林生态系统产生重要影响，气温升高与干旱胁迫对植物生长发育影响的研究受到极大关注，但不同类型植物的响应不同，有关对木本植物果实品质形成的影响机理鲜有报道。本项目在前期研究基础上，采用改进开顶气室（OTC）系统模拟控制增温环境、自动化灌溉系统控制土壤干旱水平，以宁夏优良鲜食枣品种——灵武长枣为研究对象，测定种植在模拟升温（2℃±0.5℃）与中度干旱、重度干旱交互处理环境下，灵武长枣叶片、果实中可溶性糖、果糖、蔗糖等糖分含量及代谢相关酶活性变化，研究交互处理下灵武长枣的糖分积累规律；测定灵武长枣果实中叶绿素、类胡萝卜素、类黄酮含量以及花色素苷含量及其合成相关酶活性变化，采用转录组测序技术，研究花色素苷合成相关酶的差异表达基因，从分子水平阐明气温升高和干旱胁迫对灵武长枣糖份积累和果实着色的影响机制，揭示气候变化对木本植物果实品质形成的影响机理，为经济林树种栽培与育种应对气

全球气候变化对农林生态系统产生重要影响，气温升高与干旱胁迫对植物的影响受到极大关注。灵武长枣为宁夏优良鲜食枣品种，研究果实糖分积累与着色对气温升高与干旱胁迫的响应，揭示气候变化对果实品质形成的影响机制，为栽培与繁育应对气候变化提供理论指导。.本项目采用开顶气室模拟控制增温环境、自动化灌溉系统控制土壤干旱水平，测定模拟气温升高与干旱胁迫交互处理下，灵武长枣果实糖含量、果皮花色素苷含量等，分析交互处理下灵武长枣果实糖分积累规律，筛选花色素苷合成差异表达基因和差异代谢物，通过转录组和代谢组联合分析，构建气温升高和干旱胁迫对灵武长枣果皮花青苷代谢的调控网络。揭示气温升高和干旱胁迫对灵武长枣果实糖份积累和着色的影响机理。结果表明：.（1）中度干旱胁迫有利于灵武长枣果实葡萄糖、果糖和蔗糖的积累，重度干旱胁迫减少了果实葡萄糖含量，增加了果实淀粉含量。气温升高2℃左右时，果实中葡萄糖、果糖、蔗糖和淀粉含量增加，气温升高减缓了中度干旱胁迫对可溶性糖积累的促进作用。.（2）灵武长枣果实发育前期，干旱胁迫提升了NI酶活性，促进NI（ZjNI 1、ZjNI 2）和SPS（ZjSPS 3）基因表达上调，后期降低了NI酶活性，主要促进AI、SPS（ZjSPS 1、ZjSPS 4）、SS（ZjSS 1、ZjSS 3）基因表达上调；气温升高2.0℃时促使蔗糖代谢相关酶基因表达上调，且随着干旱胁迫的加剧上调幅度越明显。.（3）气温升高2.0 ℃时通过增加果实可溶性糖含量增加花色苷合成的碳源物质，促进UFGT、PAL、DFR的活性和ZjDFR、ZjUFGT、ZjLDOX基因表达量，促进花色苷的合成积累，从而促进灵武长枣果实着色。而干旱的影响作用则相反。.（4）13个花青苷合成候选基因与6种花青苷代谢产物高度关联，其中飞燕草素和天竺葵色素是果皮呈现红色的主要花青素类物质，也是响应升温环境的主要花青苷合成代谢物。.（5）ZjCHS、ZjCHI、ZjANS、ZjDFR是灵武长枣响应气温升高与干旱的花青苷合成关键基因，气温升高通过上调花青苷合成基因来促进代谢物积累，进而促进果实着色。