外源S3307调控薏苡低温胁迫应答的抗性机理研究

Coix (Coix lachryma-jobi L) is a crop of food and medicine, which not only has high protein and lipid but also has some medicinal effects, such as anti-tumor, hypoglycemic etc. With coix nutrition, medicinal and edible value being concerned, the demand of coix expand has become more and more big. However, low temperature is a key factor of limiting heilongjiang province coix planting and growth. S3307 is a plant growth retardant, which can exert beneficial effects on alleviating various abiotic stresses, such as extreme temperature damage, drought stress, salt injury, etc. In this study,“YiLiao 5” was taken as the experimental material. Basing on coix seedlings responding to physilological mechanism of the low temperature, the study applied transcriptome and DNA methylation analyse method to test and Coix (Coix lachryma-jobi L) is a crop of food and medicine, which not only has high protein and lipid but also has some medicinal effects, such as anti-tumor, hypoglycemic etc. With coix nutrition, medicinal and edible value being concerned, the demand of coix expand has become more and more big. However, low temperature is a key factor of limiting heilongjiang province coix planting and growth. S3307 is a plant growth retardant, which can exert beneficial effects on alleviating various abiotic stresses, such as extreme temperature damage, drought stress, salt injury, etc. In this study,“YiLiao 5” was taken as the experimental material. Basing on coix seedlings responding to physilological mechanism of the low temperature, the study applied analysis method of iTRAQ technology (transcriptome) and RNA-Seq sequencing technology (proteome) to test and screen differential genes and differential protein and carry on bioinformatics analysis. Meanwhile, screening cold tolerance genes being combined with related physiological indicators under low temperature stress, the study can clear the mechanism of S3307 strengthen the resisting low temperature ability of coix, which can provide an theoretical basis for functional genes screening, Genetic transformation,strain improvement of resisting low temperature, which also provide a certain reference for S3307 in resistance to production and cold and cultivation.

薏苡是一种药食兼用的作物，不仅含有丰富的蛋白质，脂肪等，还具有抗肿瘤、降血糖等药用功效，随着人们对薏米营养、药用和食用价值的逐步认识，薏米的需求量也随之扩大。而低温是限制黑龙江省垦区薏苡种植和生长最为主要的因素。S3307是一类能够抑制赤霉素合成的植物生长延缓剂，能够减轻各种低温、干旱等非生物胁迫。本项目以“薏辽5号”为材料，在研究S3307对薏苡苗期低温生理方面的响应机制的基础上，利用iTRAQ技术（蛋白质组学）及RNA-Seq测序技术（转录组学）分析手段，研究S3307对低温胁迫下薏苡幼苗中差异基因和差异蛋白质，并进行生物信息学的联合分析。同时将筛选出的抗寒基因与低温胁迫下的相关生理指标结合，明确S3307增强薏苡耐低温能力的机理，为关键性功能基因的挖掘，基因遗传转化和耐低温性状改良等提供一定的理论基础，同时为S3307在薏苡抗性生产中的应用及寒区栽培种植提供一定的参考。

项目背景：.薏苡是一种药食兼用作物，不仅含有丰富蛋白质脂肪，还具有抗肿瘤、降血糖等药用功效，其需求量越来越大。低温是限制黑龙江省垦区薏苡种植和生长最为主要的因素之一。烯效唑（S3307）是一类能够抑制赤霉素合成植物生长延缓剂，能够减轻各种低温等非生物胁迫。.研究内容：.1、S3307对低温胁迫下薏苡幼苗生长及生理指标影响：.1）研究S3307对低温胁迫下薏苡株高、根长、茎粗和干重等影响。.2）研究S3307对低温胁迫下薏苡幼苗抗氧化物酶，渗透性物质，光合指标等影响。.3）研究S3307对低温胁迫下薏苡叶片超微结构影响。.4）研究S3307对低温胁迫下薏苡幼苗内源激素影响。.2、通过转录组测序技术，获得S3307处理前后差异表达基因。.3、采用蛋白质技术，分析鉴定S3307处理前后差异蛋白。.重要结果及关键数据：.1、S3307处理组茎粗比低温胁迫组提高11.90%，地上地下干重分别提高13.59%和10.98%。.2、S3307处理组与低温组相比，根系SOD，POD,CAT和APX分别提高16.19%、5.79%、83.83%和16.34%，叶和根中脯氨酸含量分别增加11.87%和33.42%，叶片净光合速、率蒸腾速率、气孔导度分别提高50.15%，138.1%，59.59%。.3、S3307组叶肉细胞叶绿体恢复正常，质壁分离现象有所缓解。.4、S3307处理后，根系GA3降低42.20%，叶片中ABA含量升高10.25%。.5、通过高通量测序分析，筛选出大量与苯丙酸合成、光合、糖类代谢等差异表达基因。.6、通过蛋白质组学分析，鉴定出与光合特性、应激与防御等代谢相关蛋白。.科学意义：.本项目将筛选耐低温基因和与生理指标相结合，不但能够明确烯效唑增强薏苡耐低温能力机理，为功能基因挖掘、遗传转化和耐低温性状改良等提供一定的理论基础和参考依据，同时为烯效唑在薏苡抗性生产中的应用及寒区栽培种植提供一定的依据和参考。