不同PE材料遮光下血橙转色期果皮花色苷合成及其相关基因的表达分析

采用不同透光率的PE袋对转色期血橙果实进行遮光试验,测定了不同遮光处理下血橙果皮总花色苷的动态含量和血橙果皮中12个花色苷合成相关基因的动态表达,深入探究光照与血橙果皮花色苷着色之间的关系,以期为改善生产中血橙果面着色不良问题提供解决思路。结果表明:血橙果实经过PE袋遮光后,果皮在着色时间、着色面积和着色程度上均受到阻碍,阻碍程度与PE袋的透光率相关,遮光促进了血橙果面亮度的增加。自然光照下,8个结构基因GST、ANS、CHS、DFR、F3H、UFGT、PAL、4CL和2个调节基因Ruby、MYBF1在转色期间的表达量快速增加,而不同程度的遮光阻碍了其表达,阻碍程度与PE袋的透光率相关,推测这10个基因属于血橙果皮花色苷合成受光调控的关键基因。将遮光后果皮总花色苷动态含量、关键基因的动态表达量与对应的PE袋透光数据进行综合分析,可以推测光照中调控血橙果皮花色苷合成的可能是其中的UVB、UVC紫外光。根据相关基因的动态测定结果,推测血橙果皮花色苷合成的关键时期在花后249 d开始出现,为保证外观品质,血橙采摘在花后249 d之后进行较为适宜。为预防血橙冬季落果,生产上通常采用冬季树体覆膜技术保果,为减少覆膜对血橙果面花色苷着色的影响,应选用透明PE膜或其他紫外线透过率较高的膜。     

植物对土壤钼污染的响应及其耐钼机制研究进展

钼是植物、动物和微生物必需的微量元素之一,同时也是一种重金属元素。以往对钼的研究主要关注钼缺乏对农作物产量与品质的影响及危害,对钼污染导致的生态风险及应对策略研究较少。本文在分析我国土壤钼污染现状及其生态风险的基础上,综述了钼污染对植物生长发育的影响、钼对植物的毒害阈值及其影响因子,以及植物对钼污染的耐性机制,并展望了未来土壤-植物系统钼污染的研究方向,以期为土壤钼污染的风险管控及修复提供参考。     

岗稔果制备高花色苷含量的真空浓缩果汁工艺探索

为利用岗稔果制备高花色苷含量的浓缩果汁,以花色苷含量为指标,在比较打浆过程中添加柠檬酸、抗坏血酸、锌离子对花色苷保护效果的基础上,探索了真空浓缩温度、时间、柠檬酸添加量等对岗稔果汁中花色苷含量的提高效果,并进行了正交优化和验证.结果表明:打浆时添加柠檬酸可有效保护岗稔花色苷,低剂量的抗坏血酸和锌离子才对岗稔花色苷有保护作用;果胶酶有助于提高岗稔汁中花色苷的含量;真空浓缩温度和时间对提高花色苷含量有显著作用.优化后的工艺条件为:添加0.6 g/kg柠檬酸、0.1 g/kg抗坏血酸和1.0 mg/kg硫酸锌打浆,果浆在50℃下酶解60 min,果汁在0.1 MPa真空度、65℃下真空浓缩90 min,可使果汁中的花色苷浓度达到初始值的30倍,而获得高花色苷含量的岗稔浓缩果汁.     

栽培蓝莓－园蓝的抗氧化活性及其活性化合物的定性定量

为测定栽培蓝莓－园蓝果实中的抗氧化活性及其总花色苷含量,以贵州产园蓝鲜果为原料,经甲醇处理、大孔吸附树脂分离得出抗氧化活性最好的部位。然后对其进行了制备分离得到一单体化合物,经1H－NMR、13C－NMR、ESI－MS进行了结构鉴定,利用Rp－HPLC进行了该化合物的含量测定。以该化合物为对照品,对园蓝果实中总花色苷含量进行了定量分析。研究表明：贵州产园蓝提取物富含花青素部分1mg/mL浓度的抗氧化活性与等浓度的维生素C的活性相当,鉴定的单体化合物为锦葵色素－3－O －葡萄糖,其纯度达96％,园蓝鲜果中总花青素平均含量为627．7mg/100g。指出了园蓝鲜果花色苷含量高,主成分为锦葵色素－3－O －葡萄糖,花青素具有较好的抗氧化活性。建议每人每天食用2g园蓝鲜果作为人体补充抗氧化剂的来源。     

一种富含花青素的固体饮料的工艺研究

以黑米、黑芝麻、黑豆、黑玉米、黑木耳、黑枣、麦芽糊精、木糖醇和乳粉为原料,针对中老年人群,开发出一款富含花青素的固体饮料。首先,将黑米、黑玉米、黑芝麻和黑豆进行预处理,以花青素保留率、淀粉糊化率、溶解度和膨胀度为指标,优化烘烤条件。结果表明,四者的烘烤条件分别为150℃,15 min;210℃,7 min;140℃,9 min;130℃,15 min。在此基础上,以感官品质为评价指标,通过单因素试验,初步探讨麦芽糊精添加量对产品黏稠度和稳定性的影响,以及木糖醇、乳粉、黑米、黑芝麻、黑豆和黑玉米添加量对产品的影响。在此基础上,选择黑米、黑芝麻、黑豆和黑玉米为主要因素,进行配方的L₉(3⁴)正交试验,各组分添加量为黑芝麻23.33%,黑豆11.67%,黑玉米16.67%,黑米11.67%,黑木耳3.33%,黑枣3.33%,木糖醇13.33%,麦芽糊精10%,乳粉6.67%。     

Improve Anthocyanin and Zinc Concentration in Purple Rice by Nitrogen and Zinc Fertilizer Application

Zinc (Zn) is an essential micronutrient for plant growth and development, and anthocyanin is a secondary metabolite compound generally produced under stress conditions; both have benefits to human health. Rice is a staple food crop for most of the world’s population, and purple rice is well known as a natural source of Zn and anthocyanins, but their stability depends upon many factors. This review focuses on the opportunity to increase Zn and anthocyanin compounds in purple rice grains via Zn and nitrogen (N) management during cultivation. Variation in grain Zn concentration and anthocyanin compounds is found among purple rice varieties, thus presenting a challenge for breeding programs aiming at high grain Zn and anthocyanin contents. Genetic engineering has successfully achieved a high-efficiency vector system comprising two regulatory genes and six structural anthocyanin-related genes driven by endosperm-specific promoters to engineer purple endosperm rice that can provide new high-anthocyanin varieties. Grain Zn and anthocyanin concentrations in rice can also be affected by environmental factors during cultivation, e.g., light, temperature, soil salinity and nutrient (fertilizer) management. Applying N and Zn fertilizer is found to influence the physiological mechanisms of Zn absorption, uptake, transport and remobilization to promote grain Zn accumulation in rice, while N application can improve anthocyanin synthesis by promoting its biosynthesis pathway via the use of phenylalanine as a precursor. In summary, there is an opportunity to improve both grain Zn and anthocyanin in purple rice by appropriate management of Zn and N fertilizers during cultivation for specific varieties.     

Stability of flower colors due to anthocyanin-flavone copigmentation in Japanese garden iris, Iris ensata Thunb.

The fading of flower color in bluish purple and reddish purple cultivars of Iris ensata and the in vitro stability of malvidin 3RGac5Gand petunidin 3RGac5G due to copigmentation with isovetixin under different pH conditions were examined. The bluish purple cultivars exhibited higher flower color stability than the reddish purple cultivars 2 days after anthesis. In the absence of isovitexin, malvidin 3RGac5G and petunidin 3RGac5G were not able to maintain color stability except at low pH. However, the color stability of malvidin 3RGac5G and petunidin 3RGac5G was increased by copigmentation with isovitexin under all pH conditions tested. Most remarkable was the stabilization of both anthocyanins due to the copigmentation at pH 4.2–6.2. Therefore, it can be concluded that the stability of flower color in the bluish purple cultivars of malvidin 3RGac5Gand petunidin 3RGac5G type of I. ensata is caused at least in part by the copigmentation between these anthocyanins and isovitexin. This revised version was published online in July 2006 with corrections to the Cover Date.     

红巧梅花色苷树脂静态纯化工艺研究

以红巧梅提取液为试验对象,通过考察树脂的静态吸附率和解吸率,从8种树脂中优选出DM-28为适合纯化红巧梅花色苷的树脂,并研究了DM-28纯化红巧梅花色苷的工艺参数。结果表明,DM-28静态纯化红巧梅花色苷的工艺参数为:在吸附温度为50℃,最适吸附p H 2.8,吸附时间6 h的条件下进行吸附,在40℃条件下以体积分数为90%p H 5.0乙醇溶液解吸效果最好。纯化后红巧梅花色苷色价为纯化前的4.84倍。     

两个红梨品种花色苷合成相关基因及转录因子MYB10表达模式分析

为研究不同红色梨品种着色差异的原因,以西洋梨品种红星和砂梨品种满天红为试材,通过荧光定量PCR方法,分析果皮中花色苷合成基因PAL、CHS、CHI、F3H、DFR、ANS、F3GT和转录因子MYB10基因在果实不同发育期的转录特性。结果表明,在红星中除PAL外,花色苷合成基因表达量与果皮花色苷含量变化一致,先升高后降低;在满天红中,PAL和F3GT在果实转色期表达量最高,其他基因表达量随果实发育而下降。转录因子MYB10在红星整个果实发育期表达水平都很低,在满天红转色期呈现峰值,且表达量是红星的50倍以上。红星着色程度可能由多个基因协同作用,而满天红着色可能受关键基因F3GT的影响,MYB10可能通过调控F3GT的表达从而调控满天红的着色。