冷胁迫下王百合GPAT基因保守区克隆及表达分析

以王百合为试验材料,通过同源克隆和巢式PCR方法从4℃低温诱导的王百合试管苗中分离得到了王百合GPAT基因的保守区序列,采用DNAman软件和BLASTN对该序列进行分析并分别从蛋白和基因角度分析了GPAT基因在4℃冷诱导情况下的表达情况.结果显示:(1)该保守区长744 bp,推测其编码247个氨基酸,氨基酸序列存在1个高度保守的区域(WIAPSGGRDRP),经过Blast比对分析发现,该保守区序列为LPLAT基因超级家族酶类的催化活性区,此家族多为催化酰基辅酶A(acylCoAs)或者酰基载体蛋白(acylACPs)中的酰基与受体蛋白结合的酰基转移酶类.(2)冷诱导促进GPAT基因的表达,随冷诱导时间延长,基因表达量不断增大,诱导4 h有大量表达,16 h表达量达到最高,16 h之后表达量随着冷诱导时间的延长逐渐下降,72 h时的表达量与0 h处理时基本一致.研究表明,GPAT在百合抵抗冷胁迫的过程中具有重要的作用.     

金黄花滇百合植株再生与离体快繁技术体系的建立

以金黄花滇百合(Lilium bakerianum var. aureum)的鳞片为外植体, 探讨不同部位外植体和不同配比的植物生长调节剂对愈伤组织诱导和植株再生的影响。研究结果表明, 鳞片诱导愈伤组织和不定芽的最适培养基为MS+1.0 mg∙L ^-16-BA+0.1 mg∙L ^-1NAA+30 g∙L ^-1蔗糖; 不定芽增殖的最适培养基为MS+0.5 mg∙L ^-16-BA+0.1 mg∙L ^-1NAA+30 g∙L ^-1蔗糖; 不定芽诱导小鳞茎的最适培养基为MS+1.0 mg∙L ^-1NAA+30 g∙L ^-1蔗糖; 小鳞茎膨大生根的最适培养基为1/2MS+0.01 mg∙L ^-1NAA+60 g∙L ^-1蔗糖。该研究为金黄花滇百合种质资源保护和快速繁殖提供了技术支撑。     

宜昌百合胚性愈伤组织诱导及植株再生体系的研究

采用L₉（3⁴）正交试验等方法,以野生宜昌百合（Lilium leucanthum）鳞片为外植体,分别在光照和黑暗培养条件下,研究了TDZ、NAA、2,4-D不同浓度配比对宜昌百合的胚性愈伤组织诱导效果的影响,并采用石蜡切片技术对愈伤组织进行了的组织学观察。在此基础上,探讨了NAA对体胚苗壮苗生根的影响。结果表明：在光照条件下诱导胚性愈伤组织的最佳培养基为MS+TDZ 0.5 mg·L^-1+NAA 1.0 mg·L^-1+2,4-D 0.05 mg·L^-1,诱导率为62.690%;黑暗条件下诱导胚性愈伤组织的最佳培养基为MS+TDZ 0.5 mg·L^-1+NAA 1.5 mg·L^-1+2,4-D 0.1 mg·L^-1,诱导率为59.423%。胚性愈伤组织黄绿色或深绿色,颗粒状明显;非胚性愈伤组织松散易碎、呈水渍状,经石蜡切片观察可观察到胚性愈伤组织细胞核大、胞质浓,且细胞内含丰富淀粉粒,细胞直径为50~80 μm。非胚性愈伤组织细胞较大,未见明显细胞核,直径约为100~180 μm。体胚苗壮苗生根的最适宜培养基为1/2MS+NAA 0.2 mg·L^-1+AC 1 g·L^-1,培养60 d后,幼苗移至草炭：蛭石：珍珠岩=1：1：1基质中,成活率为90%。本试验成功建立了宜昌百合鳞片胚性愈伤组织的再生体系,为宜昌百合利用胚状体进行无性育种以及种质资源的创新奠定了基础。     

Effects of short-term heat stress on oxidative damage and responses of antioxidant system in Lilium longiflorum

This paper aims to determine the changes in reactive oxygen species (ROS) and the responses of the lily (Lilium longiflorum L.) antioxidant system to short-term high temperatures. Plants were exposed to three levels of heat stress (37°C, 42°C, 47°C) for 10 h when hydrogen peroxide (H₂O₂) and superoxide (O₂⁻) production rate along with membrane injury indexes, and changes in antioxidants were measured. Compared with the control (20°C), electrolyte leakage and MDA concentration varied slightly after 10 h at 37°C and 42°C, while increased significantly at 47°C. During 10 h at 37°C and 42°C, antioxidant enzyme activities, such as SOD, POD, CAT, APX and GR, were stimulated and antioxidants (AsA and GSH concentrations) maintained high levels, which resulted in low levels of O₂⁻ and H₂O₂ concentration. However, after 10 h at 47°C, SOD, APX, GR activities and GSH concentration were similar to the controls, while POD, CAT activities and AsA concentration decreased significantly as compared with the control, concomitant with significant increase in O₂⁻ and H₂O₂ concentrations. In addition, such heat-induced effects on antioxidant enzymes were also confirmed by SOD and POD isoform, as Cu/ZnSOD maintained high stability under heat stress and the intensity of POD isoforms reduced with the duration of heat stress, especially at 47°C. It is concluded that in lily plants, the oxidative damage induced by heat stress was related to the changes in antioxidant enzyme activities and antioxidants.     

Lily pollen alkaline phytase is a histidine phosphatase similar to mammalian multiple inositol polyphosphate phosphatase (MINPP)

Phytic acid is the most abundant inositol phosphate in cells; it constitutes 1-5% of the dry weight of cereal grains and legumes. Phytases are the primary enzymes responsible for the hydrolysis of phytic acid and thus play important roles in inositol phosphate metabolism. A novel alkaline phytase in lily pollen (LlALP) was recently purified in our laboratory. In this paper, we describe the cloning and characterization of LlALP cDNA from lily pollen. Two isoforms of alkaline phytase cDNAs, LlAlp1 and LlAlp2, which are 1467 and 1533 bp long and encode proteins of 487 and 511 amino acids, respectively, were identified. The deduced amino acid sequences contains the signature heptapeptide of histidine phosphatases, -RHGXRXP-, but shares < 25% identity to fungal histidine acid phytases. Phylogenetic analysis reveals that LlALP is most closely related to multiple inositol polyphosphate phosphatase (MINPP) from humans (25%) and rats (23%). mRNA corresponding to LlAlp1 and LlAlp2 were expressed in leaves, stem, petals and pollen grains. The expression profiles of LlAlp isoforms in anthers indicated that mRNA corresponding to both isoforms were present at all stages of flower development. The expression of LlAlp2 cDNA in Escherichia coli revealed the accumulation of the active enzyme in inclusion bodies and confirmed that the cDNA encodes an alkaline phytase. In summary, plant alkaline phytase is a member of the histidine phosphatase family that includes MINPP and exhibits properties distinct from bacterial and fungal phytases.     

Histone H3 variants in male gametic cells of lily and H3 methylation in mature pollen

Histones are vital structural proteins of chromatin that influence its dynamics and function. The tissue-specific expression of histone variants has been shown to regulate the expression of specific genes and genomic stability in animal systems. Here we report on the characterization of five histone H3 variants expressed in Lilium generative cell. The gcH3 and leH3 variants show unique sequence diversity by lacking a conserved lysine residue at position 9 (H3K9). The gH3 shares conserved structural features with centromeric H3 of Arabidopsis. The gH3 variant gene is strongly expressed in generative cells and gH3 histone is incorporated in to generative cell chromatin. The lysine residue of H3 at position 4 (H3K4) is highly methylated in the nuclei of generative cells of mature pollen, while methylation of H3K4 is low in vegetative cell nuclei. Taken together, these results suggest that male gametic cells of Lilium have unique chromatin state and histone H3 variants and their methylation might be involved in gene regulation of male gametic cells.Accession numbers for the sequence data The sequences reported in this paper have been deposited in the DDBJ database gcH3 GC1174 (accession no. AB195644), gH3 GC1008 (accession no. AB195646), leH3 GC1126 (accession no. AB195648), soH3-1 GC0075 (accession no. AB195650), soH3-2 GC1661 (accession no. AB195652), genomic sequence of gcH3 (accession no. AB195645), genomic sequence of gH3 (accession no. AB195647), genomic sequence of leH3 (accession no. AB195649), genomic sequence of soH3-2 (accession no. AB195651), genomic sequence of soH3-2 (accession no. AB195653).     

淡黄花百合的组织培养与快速繁殖

以淡黄花百合的鳞片为外植体进行试管培养,筛选出各培养阶段适宜的培养基分别为:(1)丛生芽诱导,MS 6-BA 2.0 mg/L NAA 0.2 mg/L 蔗糖3%;(2)继代增殖,MS 6-BA 1.5 mg/L NAA 0.1 mg/L 蔗糖3%;(3)生根及小鳞茎生长,1/2 MS NAA 0.5～1.0 mg/L 蔗糖3% 活性碳0.1%,1/2 MS NAA 0.5 mg/L 蔗糖6% 活性碳0.1%.     

用双向电泳分析百合减数第一分裂周期蛋白质的变化

利用双向电泳方法检测到百合减数第一分裂花粉母细胞内约有130种蛋白质组分,其中有两类蛋白质呈现周期性变化。70KD／pI6.1,66KD/pI6.4,68KD/pI7.2在中期、后期消失,末期重新出现;而10KD／pI5.3则在中、后期出现、末期消人。在减数第一分裂不同时期也有多种蛋白质的合成与降解现象,20KD/pI3.7,17KD/pI3.8,16KD/pI3.7,15KD/pI3.3,11KD/pI3.8,10KD/pI3.7六种蛋白质在后期合成;蛋白质呈现出周期变化和在不同分裂时期的合成与降解可能与减数分裂不同时期的周期调控有关。     

青藏高原东南部山丹nrDNA ITS和cpDNA petB/petD 序列的分子进化特点

采用改良CTAB法提取青藏高原东南部山丹25个居群所有个体的基因组DNA,选取核基因ITS和叶绿体petB/petD区域进行PCR扩增、纯化和测序。对所有序列对位排列,其中ITS序列总长696bp,变异位点有4处,共产生7种单倍型,变异位点百分率为0.72%,（G+C）含量60.4%;petB/petD序列总长616bp,仅1处变异位点和2种单倍型,变异位点百分率为0.16%,（G+C）含量34.6%。表明山丹中,petB/petD区域较ITS序列保守,变异速率较慢。对ITS序列单倍型进行失配分布和中性检验分析发现,山丹现有分布范围可能经历了近期居群小范围扩张,AMOVA分析发现山丹居群的遗传变异主要存在于居群内,N_ST >G_ST（P>0.01）,表明山丹的遗传变异有着不显著的谱系地理结构。因此,山丹ITS序列适合该种的谱系地理学研究。