基于转录组测序的羽衣甘蓝叶色相关基因分析

叶色是羽衣甘蓝重要的观赏性状之一。本研究采用Illumina Hi-Seq2500高通量测序技术,对基因型纯合的紫叶和白叶羽衣甘蓝叶片进行转录组测序,筛选差异基因并与GO和KEGG数据库比对进行注释分析,分析羽衣甘蓝叶色形成相关基因。结果显示,获得高质量短读序共104 608 770条,筛选出紫叶相对白叶的差异表达基因1 993个,其中上调表达基因1 094个,下调表达基因899个。根据GO功能分类可分为生物过程、细胞组分和分子功能3大类64功能组。根据KEGG代谢通路分析可以分为171类,在叶色相关的类黄酮生物合成途径中黄酮醇合成酶(FLS)、二氢黄酮醇4-还原酶(DFR)上调以及类胡萝卜素生物合成途径中的类胡萝卜素β-环化酶上调与紫叶形成关系密切。本研究丰富了羽衣甘蓝的转录组信息,获得了一些差异表达基因,为进一步研究羽衣甘蓝叶色形成的遗传机制提供了有价值的信息。     

花青素调节基因VlmybA2对番茄遗传转化

以小型番茄 Micro-Tom 为材料,利用农杆菌介导法导入花青素调节基因VlmybA2。对抗性筛选出的再生植株进行 GUS 组织染色和 PCR 检测,证明外源基因已经整合到 Micro-Tom 中,转基因番茄根、茎、叶脉、果皮均呈紫色,花色为黄紫嵌合。而野生型的根为白色,茎、叶脉呈绿色,果皮为红色,花为黄色。对转基因番茄的花青素含量、叶片叶绿素含量和光合速率等生理指标进行测定,花青素含量有显著增加,叶绿素含量降低,VlmybA2基因过量表达会降低植株的光合效率,但对植株正常生长影响并不显著。VlmybA2 基因既可增加抗衰老物质花青素含量,又可作为转基因植株的报告基因。     

不同种源黄连木秋季色素含量与叶色参数的关系

该研究以陕西汉中、河南林州、河北涉县和北京中国科学院植物研究所4个种源黄连木(Pistacia chinensis Bunge)的苗木为对象,用分光光度计和色差仪对其叶绿素、类胡萝卜素、花色素苷含量及叶色参数(L*、a*、b*)进行了测定分析,探讨不同种源苗木秋季叶色变化规律及差异,揭示黄连木叶色呈现与叶片色素含量之间的内在关联,为筛选适合城市绿化的优良黄连木种源提供依据。结果表明:(1)在秋季叶片转色期,随着时间的推移,4个种源黄连木叶片的叶绿素、类胡萝卜素和花色素苷含量的比例呈现不同的变化趋势,其中:河北种源的花色素苷含量较高,叶片呈现红色;陕西种源叶绿素含量较高,叶片呈现绿色的时间较长;河南、北京种源处于两者之间。(2)各个种源黄连木的叶色参数a*值(红/绿)均与花色素苷含量呈正相关关系,与叶绿素含量呈负相关关系,且相关系数均达到显著水平(P0.05),各个种源叶色参数L*值(光泽明亮度)也与叶绿素含量间表现出显著或极显著的正相关性。研究发现,河北种源黄连木秋季的叶色最红,陕西种源黄连木叶片呈现绿色的时间最长;色差仪的应用实现了叶色和各色素含量间量化的关系。     

不同叶色三叶海棠叶片成色色素分析

结合民族植物学和药理学的研究方法,对西双版纳地区傣族、哈尼族和基诺族等3个少数民族民间利用番石榴（Psidium guajava）、余甘子（Phyllanthus emblica）和水柳（Homonoia riparia）的传统知识进行调查研究及体外抗菌活性实验。结果表明：番石榴和余甘子在村寨中较为常见,当地少数民族将其种植于庭院中,常作为果蔬食用,食用番石榴嫩叶可缓解拉肚子的症状,治疗腹痛、腹泻。水柳生长在水边,傣族会将其叶作为腌酸鱼的配料之一。根据文献记载,番石榴、余甘子和水柳的叶部位作为药使用时,常煎水外洗,治疗皮肤瘙痒。对这3种药用植物叶部位采用80%乙醇浸泡制备的提取物进行体外抗菌实验,结果显示番石榴、余甘子和水柳3种药用植物对金黄色葡萄球菌和大肠埃希菌均有较好的抑菌和杀菌活性,其最小抑菌浓度MIC在98~390 μg·mL 1之间,最小杀菌浓度MBC在98~781 μg·mL 1之间。番石榴和水柳叶对铜绿假单胞菌有一定抑菌和杀菌活性,其MIC和MBC范围均为6 250~12 500 μg·mL 1。由此可见,这3种药用植物的民间利用具有一定的合理性和药用开发价值。     

Biochemical and molecular analysis of a temperature-sensitive albino mutant in kale named “White Dove”

“White Dove” is a mutant in kale (Brassica oleracea var. acephala f. tricolor), which exhibits a mutant albino phenotype in the interior of the plant under low temperature conditions. Chlorophyll content in “White Dove” was dramatically reduced under low temperature conditions, while the content in “Green Dove” decreased slightly under the same conditions. The levels of five chlorophyll precursors suggested that chlorophyll biosynthesis in white kale was inhibited by low temperature stress at the step of Pchlide. However, Mg-Proto IX was not inhibited in white kale grown under low temperature conditions. The results of quantitative RT-PCR illustrated that the chlorophyll biosynthetic genes in the white cultivar were dramatically down-regulated by low temperature stress from the step of POR, while CISC and DBB1B in the white cultivar were dramatically induced under low temperature conditions. The results of transmission electron microscopy analysis showed that there were normal chloroplasts in the young leaves of white kale grown at 20 °C, whereas proplastids were observed in white kale grown at 5 °C. These results strongly suggested that low-temperature stress significantly inhibited plastid development in the young leaves of white kale, and repressed chlorophyll biosynthesis at the step of Pchlide by down-regulating the expression of downstream chlorophyll biosynthetic genes, resulting in undifferentiated proplastids and the albino phenotype observed in young leaves. Several genes associated with chlorophyll accumulation were also affected by low temperature conditions in white kale, especially CISC and DBB1B.     

苗期遮光光质对生姜光合及生长的影响

以不同颜色塑料薄膜为遮光材料,研究了苗期遮光光质对生姜生长及光合作用的影响.结果表明:幼苗覆膜期,生姜叶片叶绿素含量以蓝膜及绿膜处理较高,白膜次之,红膜较低;叶片P_n则以绿膜处理较高,为14.9 μmol·m^-2·s^-1（第4叶）,分别较白膜、红膜及蓝膜提高5.7%、10.4%和18.3%.旺盛生长期撤膜后,P_n较幼苗期升高,但处理间的变化趋势与幼苗期相似;新生叶片叶绿素含量除红膜处理较低外,其它处理无显著差异,但下位叶片叶绿素含量则以蓝膜和红膜处理显著低于绿膜和白膜处理.蓝膜处理生姜植株茎秆增高、变细,分枝数较少;绿膜处理植株根、茎、叶及根茎鲜质量较高,白膜、红膜及蓝膜处理依次降低,收获时,其产量分别达57 000、53 709、51 487和48 712 kg·hm^-2.说明生姜苗期采用绿膜遮光,可增强叶片光合作用,促进植株生长,提高生姜产量.     

枫香秋季变色期叶色变化及其生理基础

为探究秋季枫叶呈色的关键生理因素,该文以转色期叶色为绿色、黄色和红色的枫香单株为试材,研究了L^*、a^*、b^*值变化与叶片色素、可溶性糖及可溶性蛋白质含量变化的相关性。结果表明:(1)在变色期,3种色彩枫香叶片叶绿素a、叶绿素b、总叶绿素和类胡萝卜素均大量降解,花色素苷不同程度积累。(2)绿色叶单株叶绿素和类胡萝卜素始终保持较高含量,花色素苷含量上升4.2倍,叶片内色素含量比值始终保持稳定; 黄色叶单株叶绿素和类胡萝卜素含量最低,花色素苷含量上升4.4倍,b^*值与叶绿素含量极显著负相关,与类胡萝卜素含量显著负相关,与花色素苷/类胡萝卜素含量比值极显著正相关; 红色叶单株叶绿素和类胡萝卜素含量略高于黄色叶单株,花色素苷含量上升27.2倍,a^*值与叶绿素含量、类胡萝卜素含量极显著负相关,与花色素苷含量显著正相关,与色素含量比值无显著相关性。(3)红色叶单株具有较高的可溶性糖含量和可溶性蛋白质含量。因此,在枫香叶片变色期,保持较高的叶绿素和类胡萝卜素含量,维持色素含量比值稳定使叶片呈现绿色; 叶绿素和类胡萝卜素的大量降解,以及花色素苷/类胡萝卜素含量比值的升高使叶片呈现黄色; 叶绿素的降解和花色素苷的大量合成使叶片呈现红色。     

不同叶色红栌叶片中色素含量、酶活性及内含物差异的研究

为明确秋季不同叶色美国红栌叶片的生理差异,以秋季同一植株上红色、中间色、绿色三种颜色的美国红栌叶片为试材,测定了叶片中色素物质含量、酶活性以及叶片可溶性内含物的含量,结果表明：在红色叶片中,叶绿素含量较低,PAL、POD酶活性较高,花青素苷/叶绿素的比值较大,从而使叶色显现红色;而在绿色叶片中,叶绿素含量较高,PAL、POD酶活性较小,花青素苷/叶绿素的比值较低,叶片显现绿色。通过可溶性内含物测定可知,在红色叶片中的可溶性糖和蛋白质含量相对较高,均与花青素苷/叶绿素的比值达到显著相关水平,表明这些内含物的积累有利于花色素苷的合成。     

不同色彩珙桐叶片和苞片解剖结构及色素含量比较研究

以生长于同一生境下的粉红珙桐(粉红色叶片、苞片)与普通珙桐(绿色叶片、白色苞片)为试材,对比两种色彩珙桐叶片/苞片解剖结构和色素含量的差异,以揭示珙桐色彩转变的规律。结果显示：(1)两种珙桐叶片均属于异面叶类型,栅栏组织由一层长柱形细胞整齐排列而成,海绵组织排列疏松,部分粉红叶片的上表皮细胞向外凸起,绿叶无此现象;粉红叶片的总厚度及其表皮角质层、栅栏组织和海绵组织厚度都高于绿叶,而表皮较薄。(2)两种珙桐苞片均无栅栏组织和海绵组织的分化,粉红苞片上表皮细胞明显隆起,上表皮角质层增厚,而下表皮变薄。(3)粉红叶片的类黄酮、花色苷含量分别是绿色叶片的1.52倍、3.67倍,两者的光合色素含量无显著差异,但粉红叶片的叶绿素a/b值比绿色叶低很多;粉红苞片花色苷含量显著高于白色苞片,而两者类黄酮含量差异不大。研究表明,花色苷是珙桐叶片和苞片色彩转红的直接因素,类黄酮有助于叶片呈红色;粉红珙桐叶片/苞片的解剖结构发生了一定变化,对光能的利用效率更高,对阴湿环境的适应性增强。     

Association of red coloration with senescence of sugar maple leaves in autumn

We evaluated the association of red coloration with senescence in sugar maple (Acer saccharum Marsh.) leaves by assessing differences in leaf retention strength and the progression of the abscission layer through the vascular bundle of green, yellow, and red leaves of 14 mature open-grown trees in October 2002. Computer image analysis confirmed visual categorization of leaves as predominantly green, yellow or red, and chemical quantification of leaf pigment concentrations verified that leaf color reflected underlying differences in leaf biochemistry. Significantly lower chlorophyll concentrations within red and yellow leaves indicated that senescence was more advanced in leaves from these color categories relative to green leaves. Among leaf types, only red leaves contained high concentrations of anthocyanins. There were significant differences in leaf retention capacity among color categories, with the petioles of green leaves being the most firmly attached to twigs, followed by red and then yellow leaves. Microscopic analysis indicated that yellow leaves had the most advanced extension of the abscission layer through the vasculature, with green and red leaves having significantly less abscission layer progression than yellow. A more limited progression of the abscission layer through vascular bundles may be evidence of delayed leaf senescence that could extend resorption of mobile leaf constituents. Together, results from this study suggest an association between leaf anthocyanin content and functional delays in senescence.     

The anti-photooxidation of anthocyanins-rich leaves of a purple rice cultivar

In the leaf of rice (Oryza sativa L.) cultivar Yunnan purple rice,the anthocyanins with an obvious absorption peak at 530nm were distributed in the cells of upper and lower epidermis,bulliform tissue and bristle. The maximal photosynthetic oxygen evolution rate and chlorophyll content in flag leaves were 28% and 23%,respectively,more than the common green leaf rice cultivar Chijiaoru-anzhan. Higher chlorophyll content is probably one of the physiological adaptations for enhancing light harvesting capacity of the antenna in photosystems in this cyanic leaves species. Upon the photooxidation of leaf segments mediated by methyl viologen in weak light for 3 days,the distinct bleaching of anthocyanins in purple rice was associated with the reduction of scavenging ability to DPPH· free radical ability and the increase in membrane leakage rate. But almost no changes in contents of flavonoids and total phenolics were observed. Chlorophyll fluorescence parameters Fv/Fo,qP and φPSⅡ decreased with the increase in NPQ and DES of xanthophylls cycle after photooxidation treatment. Green rice leaves showed more decrease in DPPH· scavenging rate and more increase in cell membrane leakage rate but showed a trace of anthocyanins during photooxidation. It is sug-gested that anthocyanin may be a beneficial and primary antioxidant in sun cyanic rice leaves against oxidative stress induced by environmental adversity. And photooxidation could induce different changing patterns of anthocyanins between the tested purple and green rice leaves.     

南天竹不同叶色与若干生理生化指标关系的研究

本文研究南天竹不同叶色的叶片叶绿素、花青素、可溶性糖含量和气孔密度、POD、CAT活性的变化。结果表明,南天竹叶色差异与花青素、叶绿素含量有关,绿叶花青素含量低、叶绿素含量高;红叶则相反。此外,红叶下表皮气孔数目少,气孔小;绿叶气孔数目多,气孔大。红叶的可溶性糖含量明显高于绿叶,而POD和CAT活性低于绿叶。     

The anti-photooxidation of anthocyanins-rich leaves of a purple rice cultivar

In the leaf of rice (Oryza sativa L.) cultivar Yunnan purple rice, the anthocyanins with an obvious absorption peak at 530nm were distributed in the cells of upper and lower epidermis, bulliform tissue and bristle. The maximal photosynthetic oxygen evolution rate and chlorophyll content in flag leaves were 28% and 23%, respectively, more than the common green leaf rice cultivar Chijiaoruanzhan. Higher chlorophyll content is probably one of the physiological adaptations for enhancing light harvesting capacity of the antenna in photosystems in this cyanic leaves species. Upon the photooxidation of leaf segments mediated by methyl viologen in weak light for 3 days, the distinct bleaching of anthocyanins in purple rice was associated with the reduction of scavenging ability to DPPH · free radical ability and the increase in membrane leakage rate. But almost no changes in contents of flavonoids and total phenolics were observed. Chlorophyll fluorescence parameters Fv/Fo, qP and ϕ_PSII decreased with the increase in NPQ and DES of xanthophylls cycle after photooxidation treatment. Green rice leaves showed more decrease in DPPH · scavenging rate and more increase in cell membrane leakage rate but showed a trace of anthocyanins during photooxidation. It is suggested that anthocyanin may be a beneficial and primary antioxidant in sun cyanic rice leaves against oxidative stress induced by environmental adversity. And photooxidation could induce different changing patterns of anthocyanins between the tested purple and green rice leaves.     

光对紫甘蓝花青素合成代谢影响及基因表达模式分析

为了研究光对紫甘蓝花青素合成代谢影响及其调控机制,以“早红”紫甘蓝为试验材料,普通甘蓝“丰园913”（青甘蓝）为对照,对生长1周的幼苗进行遮光处理和光照处理,采用pH差示法测定花青素含量,半定量RT-PCR分析花青素合成途径结构基因表达模式。结果表明：光照处理与遮光处理后,除PAL、UFGT外,紫甘蓝结构基因表达无明显差异,无光条件下,紫甘蓝幼苗仍着色明显,而青甘蓝幼苗完全白化;与青甘蓝相比,紫甘蓝花青素合成途径下游结构基因表达量明显增高,幼苗着色深,揭示紫甘蓝花青素的大量积累与下游结构基因的表达密切相关。     

Light Intensity Affects the Coloration and Structure of Chimeric Leaves of <i>Ananas comosus</i> var<i>. bracteatus</i>

Ananas comosus var. bracteatus is an important ornamental plant because of its green/white chimeric leaves. The accumulation of anthocyanin makes the leaf turn to red especially in the marginal part. However, the red fades away in summer and winter. Light intensity is one of the most important factors affecting leaf color along the seasons. In order to understand the effects of light intensity on the growth and coloration of the chimeric leaves, Ananas comosus var. bracteatus was grown under full sunlight, 50% shade and 75% shade for 75 days to evaluate the concentration of pigments, the color parameters (values L*, a*, b*) and the morpho-anatomical variations of chimeric leaves. The results showed that a high irradiance was beneficial to keep the chimeric leaves red. However, prolonged exposure to high irradiance caused a damage, some of the leaves wrinkled and even burned. Shading instead decreased the concentration of anthocyanin and increased the concentration of chlorophyll, especially in the white marginal part of the leaves. Numerous chloroplasts were observed in the mesophyll cells of the white marginal part of the chimeric leaves under shading for 75 days. The increase in chlorophyll concentration resulted in a better growth of plants. In order to balance the growth and coloration of the leaves, approximately 50% shade is suggested to be the optimum light irradiance condition for Ananas comosus var. bracteatus in summer.