Studies of clomazone mode of action

Intact spinach chloroplasts were used to determine if clomazone, 5-OH clomazone, and/or 5-keto clomazone inhibited the chloroplastic isoprenoid pathway. When isopentenyl pyrophosphate was used as a precursor, neither clomazone nor the clomazone metabolites (5-OH clomazone and 5-keto clomazone) inhibited the formation of products separated by HPLC in the organic phase. However, when pyruvate, a substrate for the first committed step of the pathway, was used as a precursor, both 5-keto clomazone and fosmidomycin reduced the formation of a non-polar product and increased the formation of a polar product in the organic phase. Only 5-keto clomazone, not 5-OH clomazone or clomazone, inhibited the formation of an additional product other than fosmidomycin in the aqueous phase from pyruvate incorporation. In an in vitro assay, 5-keto clomazone inhibited DXP synthase, the enzyme catalyzing the first committed step of the chloroplastic isoprenoid pathway. Therefore, our studies show that neither clomazone nor 5-OH clomazone inhibits the chloroplastic isoprenoid pathway, only 5-keto clomazone does.     

2种保鲜方法对脐橙果实风味和色泽变化的影响

以赣南纽荷尔脐橙冷藏和留树保鲜果实为材料,进行品质分析,并运用HPLC技术分析果皮与果肉的类胡萝卜素组成和色泽变化。结果表明,冷藏果实固酸比(17.08)比对照(21.36)降低了4.28;而留树保鲜果实固酸比增加到33.33,约为冷藏果实的2倍;冷藏果实在缺乏光照条件下仍可合成类胡萝卜素,尤其是β-隐黄质和玉米黄质,但是果皮偏黄色,可能是由类胡萝卜素的组成、比例及空间分布的改变引起的;留树保鲜类胡萝卜素的合成积累约为冷藏的1.5倍,果皮呈现鲜艳的橙色,是紫黄质和(9Z)-紫黄质大量积累的结果。     

Improved protocol for Agrobacterium mediated transformation of tomato and production of transgenic plants containing carotenoid biosynthetic gene CsZCD

Improved protocol for Agrobacterium mediated transformation of tomato (Lycopersicon esculentum) Micro-Tom was developed to use in corporation of the carotenoid biosynthetic genes CsZCD (Crocus zeaxanthin 7,8-cleavage dioxygenase). From these experiment, a transformation methodology using explants from cotyledons cultured for 1 day on the medium with zeatin 2 mg/L, IAA 0.1 mg/L, carefully submerged in the Agrobacterium inoculum for 20 min, then concultured with the agrobacterium for 3 days on the same medium, followed by a transfer to the same medium with 500 mg/L cefotaxin for 3 days and then by a transfer to the same medium with 100 mg/L kanamycin and 500 mg/L carabenillin for 6–8 weeks and resulted in a greater than 20% transformation efficiency in the concentration of Agrobacterium OD600 = 0.2 tested. In this transformation method, no feeder layers were used and the subculture media was minimal. Among the Agrobacterium concentrations of OD600 = 0.2, 0.5 and 1.0, the best transformation efficiency, 20.87%, was obtained by using OD600 = 0.2, which was significantly higher than that of OD600 = 1.0. The presence of the inserted target genes was checked using a rapid and efficient PCR test. The protocol was successfully employed in the production of transgenic Micro-Tom tomato containing the carotenoid biosynthesis CsZCD under constructive promoter. This procedure represents a simple, efficient and general means of transforming tomato.     

稀土对南果梨着色及果实品质的影响

选取6 a生生长势与负载量相似的南果梨树20株,以300×10-6、400×10-65、00×10-6mol/L 3个Lenth浓度喷施(5次重复),每隔5 d采摘树体外围果实,每株3次重复,直至采收期(9月11日),分别测定其相关指标。来研究稀土(Lenth)对南果梨成熟期间花青素、叶绿素、类胡萝卜素以及果实品质的影响。结果表明:Lenth处理有效地促进了南果梨果皮花青素含量,降低了果皮叶绿素和类胡萝卜素含量,增加了果肉可溶性糖含量及单果重,降低了有机酸含量。Lenth最佳的施用浓度为500×10-6mol/L。     

类萜生物合成抑制剂概述

本文综述了类萜生物合成抑制剂的主要种类、作用部位、作用机制、除草对象、在植物体内的吸收与传导以及混用与增效等,提出了类萜生物合成抑制剂进一步研究的方向。     

Effects of dietary supplementation of carotenoids on survival, growth, pigmentation, and antioxidant capacity of characins, Hyphessobrycon callistus

This study aimed to find out if dietary carotenoid (CD) supplement could make differences in survival, growth, pigmentation, and antioxidant capacity of characins Hyphessobrycon callistus, an ornamental fish. Two types of CD and its combination (AX — astaxanthin, BC — β-carotene, MX — 1:1 combination of AX and BC) at three concentrations (10, 20, and 40 mg/kg) were used resulting in nine pigmented diets. A diet without CD supplement served as control. No differences in growth and survival of the fish among treatments were found after 8 weeks rearing. Disregarding the types of dietary CD, AX dominated (> 98%) the body CD, indicating that this fish converted most dietary BC into body AX for storage. Body AX and BC content increased with increasing dietary CD concentration. Body AX in BC-fed fish was lower than that in both AX- and MX-fed fish. No difference in body AX was found between AX- and MX-fed fish, and in body BC in all pigmented fish. Serum total antioxidant status [TAS], serum antioxidant enzymes (superoxide dismutase [SOD], glutathione peroxidases [GPx]) and serum transaminases (alanine aminotransferase [ALT], aspartate aminotransferase [AST]) were chosen as indices of fish antioxidant capacity. Antioxidant activities changed with dietary CD type and concentration. Pigmented fish had lower SOD, GPx and ALT than control fish; dietary CD types only affected SOD and ALT in fish. AX-fed fish had the lowest SOD. Dietary AX had more numbers of negative correlations with antioxidant parameters in fish than BC.     

Analysis of Major Carotenoid Composition and Its Content of Citrus Fruit

a-carotene, β-carotene, lycopene, β-cryptoxanthin, zeaxanthin and lutein content of fruits in53 citrus cultivars were determined using HPLC. In both peel and pulp of citrus fruit, the major carotenoidswere lutein, zeaxanthin and β-cryptoxanthin. β-carotene content was relatively low and extremely low was theamount of or-carotene. Among the 53 cultivars tested, lycopene was detected only in pulp of Cara Cara navelorange. Carotenoid content in both peel and pulp of citrus fruit was the highest in Citrus reticulata Blanco andlowest in Citrus grandis Osbeck. Consequently, as far as the health protection value is considered, fruit ofCitrus reticulata Blanco ranks probably higher than other citrus fruits. In fruit of most Citrus retieulatavarities, β-cryptoxanthin was the main carotenoid component in pulp and its amount approximated that of lu-tein in peel. Content of lutein, zeaxanthin and β-cryptoxanthin in peel was about 2.5 - 15 times that in pulp onthe basis of fresh weight. Thus peel was inferred to be the principal location for the carotenoid stock in citrus fruit.     

胡萝卜渣干燥过程中水分、类胡萝卜素的变化规律及工艺比较

 【目的】胡萝卜汁加工中产生了大量的废渣，需要较佳的干燥工艺保存好胡萝卜渣中的类胡萝卜素，以利于综合利用。【方法】采用热风干燥、真空干燥以及联合干燥工艺对胡萝卜渣干燥过程中含水量及类胡萝卜素的动态变化规律进行研究与比较。【结果】采用先热风85℃干燥45 min后再真空75℃干燥，当胡萝卜渣含水量达到8%时，干燥时间最短，为135 min，类胡萝卜素的损失率最少，仅为2.1%。【结论】热风－真空联合干燥技术能在较短的干燥时间内较大程度地保存胡萝卜渣中的类胡萝卜素，为较佳的胡萝卜渣干燥工艺。     

水杨酸对葡萄幼苗叶片膜脂过氧化的影响

 以一年生京秀葡萄 (Vitisviniferacv .Jingxiu)扦插苗为试材 ,研究了外源水杨酸对葡萄叶片膜脂过氧化的影响。结果表明 ,喷施 1× 10 -4mol·L-1的水杨酸后 ,葡萄幼苗叶片的丙二醛含量下降 ,可溶性蛋白质含量升高 ,抗氧化酶抗坏血酸过氧化物酶、谷胱甘肽还原酶活性和抗氧化剂类胡萝卜素、谷胱甘肽、抗坏血酸含量显著升高。水杨酸可能通过提高葡萄叶片对膜脂过氧化的抗性来诱导其对胁迫的抗性。     

彩色大白菜新品种“金冠2号”的选育

在1996年育成彩色大白菜材料的基础上,应用优良自交系92S24等采用杂交、自交,育成了系列彩色大白菜自交系,2002年从20多个杂交组合中筛选“金冠2号”新品种(01S1024×01S915)。该品种叶球叠抱,高头球形,株高41 cm,株幅65 cm;球形指数1.4;外叶绿色,球叶外层2~3片叶为绿色,内层叶色为橙色,在阳光下叶色稍变红;单球净重2.5~3.0 kg,净菜率为75%以上,结球紧实,营养丰富,商品性好;球叶类胡萝卜素含量为优质普通大白菜秦白二号的3.47倍,vC、可溶性糖、粗蛋白分别提高44%、36%和18%,干物质提高11.73%,粗纤维减少26.0%。一般净菜产量为90.0 t/hm2左右,高抗病毒病、霜霉病、干烧心、软腐病和黑斑病,生育期75~80 d。2004年通过陕西省新品种鉴定。