Stigma-Specific Comparative Proteomic Analysis Reveals the Distyly Response to Self-Incompatibility in Plumbago auriculata Lam

In plants,heteromorphic self-incompatibility(HetSI)is a strategy for avoiding self-pollination and promoting outcrossing,and during this process,numerous protein-protein interaction events occur between the pistil and pollen.Previous studies in Primula and Fagopyrum that focused on HetSI systems have provided interesting insights;however,the molecular mechanism underlying HetSI remains largely unknown.In this study,we profiled the proteome of Plumbago auriculata stigmas before and after self-incompatible(SI)and self-compatible(SC)pollination.Comparative analyses were conducted by 4D-DIA(Four-dimensional data independent acquisition),a promising technology that increases the sensitivity and reduces the spectral complexity of proteomic analysis by adding a fourth dimension,ion mobility.The results revealed 33387 peptides and 5311 proteins in all samples.The pathways in which the differentially expressed proteins(DEPs)identified in the P×P(Pin style self-pollinated with pin pollen)vs.PS(Pin style)and T×T(Thrum style self-pollinated with thrum pollen)vs.TS(Thrum style)comparisons were significantly enriched were biosynthesis of secondary metabolites and pentose and glucuronate interconversions.In the P×T(Pin style cross-pollinated with thrum pollen)vs.PS and T×P(Thrum style cross-pollinated with pin pollen)vs.TS comparison,the top three pathways were biosynthesis of secondary metabolites,pentose and glucuronate interconversions,and phenylpropanoid biosynthesis.The phenylpropanoid biosynthesis,cutin,suberine and wax biosynthesis,and flavonoid biosynthesis pathways were enriched in the P×T vs.P×P comparison,and starch and sucrose metabolism,glycerophospholipid metabolism,and alpha-linolenic acid metabolism were abundant in the T×T vs.T×P comparison.The enriched pathways between PS and TS were the biosynthesis of secondary metabolites,phenylpropanoid biosynthesis,and pentose and glucuronate interconversion.Self-incompatibility protein S1(SI S1),Mitogen-activated protein kinase 3/4(MPK3/4),Mitogen-activated protein kinase kinase 2/3(M2K2/3),Exocyst complex component EXO70A1(E70A1)and Thioredoxin H1/2(TRXH1/2)were found to be HetSI-related candidates,and O-fucosyltransferase 23(OFT23),3-ketoacyl-CoA synthase 6(KCS6),Receptor-like protein kinase FERONIA(FERON),Fimbrin-5(FIMB5),Pollen-specific leucine-rich repeat extensin-like protein 4(PLRX4),Transcription initiation factor IIB-2(TF2B2)and Pectinesterase 1(AL11A),etc.,were identified as other regulatory transducers.These findings combined with our morphological and reactive oxygen species(ROS)intensity analyses indicate that P.auriculata has typical dry-stigmas and that the HetSI mechanism might differ between the pin and thrum.SI S1 might be the key factor in HetSI,and ROS are overexpressed during SC pollination to rapidly activate the mitogen-activated protein kinase(MAPK)-mediated phosphorylation of E70A1 to maintain stigma receptivity in plants with HetSI.

The Self-incompatibility (S) Locus of Antirrhinum Resides in a Pericentromeric Region

The self-incompatibility ( S) loci from the Solanaceae, Rosaceae and Scrophulariaceae encode a class of ribonucleases, known as S RNases, which have been shown to control the pistil expression of self-incompatible reaction. In the former two families, the S loci have been shown to be located near centromere. However, the chromosomal location of the S locus in Antirrhinum, a species of the Scrophulariaceae, is not known. To determine its chromosomal location and genomic organization, an S-2 RNase gene and its corresponding 63 kb BAC clone were separately used for fluorescence in situ hybridization (FISH) of mitotic metaphase chromosomes of a self-incompatible Antirrhinum line Of S2S5. The results showed that the S-2 RNase detected a doublet signal near the centromere of the smallest chromosome (2n = 16). Two separate doublet signals of the tested BAC sequence were shown on both sides of the centromeres of all eight pairs of the chromosomes, suggesting that the Antirrhinum S locus is located in a pericentromeric region. Furthermore, a retrotransposon, named RIS1 (retrotransposon in the S locus), which has not been identified yet in. Antirrhinum, was found next to S-2 RNase. Taken together, the centromeric location of the S locus from the three S-RNase-based self-incompatible families provides a further support on a common origin of their evolution as well as suppressed recombination.

Recent advances in identification of male specificity determinant and its function in S-RNase-mediated gametophytic self-incompatibility

S-RNase-mediated gametophytic self-incompatibility （GSI） is controlled by a multiallelic S-locus at which two separate genes, the female （pistil） and male （pollen） specificity determinants, are tightly linked. This review described both the identification of pollen specific F-box genes, SLF/SFBs, in Antirrhinum, Petunia and Prunus species and the demonstration of SLF/SFB as pollen determinant together with their functions in GSI response. Recent studies of how the pollen determinant functions in pollination reaction revealed that pollen determinant interacted with S-RNases in a non-allele-specific manner. It targeted all of the non-self S-RNases for ubiquitination through a functional SCF complex and subsequent degradation via 26S proteasome pathway in compatible reaction. It allows pollen tube to reach into the embryo sac and to finish double fertilization. In incompatible response, the intact self S-RNases were left to function as a cytotoxin that degrades self-pollen tube RNA, resulting in the cessation of pollen tube growth.

Identification of Self-Incompatibility Genotypes in Some Sand Pears (Pyrus pyrifolia Nakai) by PCR-RFLP Analysis

The identification of self-incompatibility genotype （S-genotype） will be useful for selection of pollinizers and design of crossing in cultivar improvement of sand pear. This paper reported the identification of self-incompatibility genotypes of seven Chinese and two Japanese sand pear cultivars using PCR-RFLP analysis and S-RNase sequencing. The Sgenotypes of these cultivars were determined as follows： Huali 1 S1S3, Shounan S1S3, Xizilti S1S4, Qingxiang S3S7, Sanhua S2S7, Huangmi （Imamuranatsu） S1S6, Huali 2 S3S4, Baozhuli S7S33, Cangxixueli S5S15. S-RNase alleles （S1 to S9） in sand pear could be identified effectively by PCR-RFLP analysis.

Heterosis of Double Low Self-incompatibility in Oilseed Rape(Brassica napus L.)

66 F 1 hybrids, produced by 3 double low self-incompatible lines and 22 varieties with a North Carolina II (NCII) crossing design, were tested for their heterosis in Wuhan, China during two growing seasons from 1999 - 2001. The results showed that significant differences were found between F1s and their parents for yield per plant and seed oil content. Mid-parent heterosis of these two characters ranged from 5.50% -64.11% and from 1.55% -7.44% respectively. Heterosis for seed yield per plant was greater than that of seed oil content. For yield components, heterosis of total number of siliques per plant was the highest, followed by seed number per silique and 1 000 seeds weight. Significant genotype-by-year interaction was found for seed yield per plant. Results from correlation and combining ability analysis indicated that parental effects on its F! hybrid depended on characters, seed yield per plant was affected by both additive and non-additive effects, and seed oil content was affected mainly by additive effect. When designing hybrid programme, parents might be selected by GCAs and variances of SCAs of parents for the characters affected by both additive and non-additive effects, and by the sum of GCAs of female and male parents for the characters mainly affected by additive effects.

Self-incompatibility Characteristics of 34 Apricot Cultivars in Xinjiang

[ Objective] This study aimed to explore the relationship between self-incompatibility strength and characteristics related to pollination and fertilization of different apricot varieties in Xinjiang. [ Method] The pollen amount, pollen germination rate, pollen tube growth status and fruiting setting rate by self-pollina- tion of 34 apricot cultivars in Xinjiang were determined, to analyze the self-incompatibility of different apricot cultivars. [ Result] The average pollen amount per anther of 34 apricot eultivars was 1 213.7, and the average pollen germination rate was 46.0%. There were great differences in the self-incompatlbility of different cuhivars ; most pollen tubes of the euhivars with high self-incompatibility stopped elongating at 1/3 or 1/2 part of the styles, and only a few pollen tubes of the euhivars with low self-incompatibility reached the ovary, and the normal fertilization ratio was significantly lower than that in self-compatible cultivars. [ Conclusion] Among the 34 apricot cuhivars, only 6 cuhivars were self-compatible and the others exhibited gametophyte self-incompatibility. In addition, the fruit setting rate by self-pollination was low.

多壁碳纳米管对水蕨配子体发育及孢子体产生的影响

探究多壁碳纳米管在水蕨配子体发育及孢子体产生中的作用,以期为濒危蕨类植物的保护和繁育奠定基础。以蕨类模式植物水蕨(Ceratopteris thalictroides)为供试材料,设置0(对照)、0.5、1.0、2.5、5.0 mg·L^(-1)多壁碳纳米管5个处理组,采用光学显微镜观察不同质量浓度多壁碳纳米管对水蕨配子体发育及孢子体产生的影响。结果显示:与对照组相比,0.5~2.5 mg·L^(-1)多壁碳纳米管处理可使水蕨孢子萌发提前约15 d,其中,0.5 mg·L^(-1)多壁碳纳米管对水蕨孢子萌发的促进效果最好,0.5~1.5 mg·L^(-1)多壁碳纳米管对丝状体和片状体产生的促进效果最好,2.5 mg·L^(-1)多壁碳纳米管对原叶体和孢子体产生的促进效果最好。高质量浓度(5.0 mg·L^(-1))多壁碳纳米管处理会导致部分配子体出现畸形,精子器退化,细胞中叶绿体出现失绿现象,部分发育出的孢子体上的细胞也出现叶绿体失绿等衰退现象。此外,多壁碳纳米管的加入促进了水蕨雄配子体的产生。综上所述,0.5~2.5 mg·L^(-1)多壁碳纳米管处理可以明显促进水蕨配子体发育和孢子体的产生,且精子器数量明显增多,有雌雄同株和雌雄异株配子体同时出现,高质量浓度多壁碳纳米管处理会使水蕨配子体发育出现“高浓度抑制”现象,在实际应用过程中应根据具体的需要选择相应的添加量。

棉花CMS-D2和CMS-D8不育系线粒体全基因组比较分析

【目的】探究哈克尼西棉不育胞质(CMS-D2)和三裂棉不育胞质(CMS-D8)的不育系线粒体基因组之间的序列结构差异,为筛选鉴定不育相关基因奠定基础。【方法】根据D2A和D8A这2个不育系的线粒体基因组测序组装结果,使用Synteny and Rearrangement Identifier(Sy RI)软件鉴定结构变异,用Plotsr可视化分析包含共线性及非共线性区域的重组变异位点。以D8A线粒体基因组注释结果为参考,用D2A线粒体基因组注释的开放阅读框(open reading frame,ORF)编码的氨基酸序列进行tblastn比对,筛选出D2A线粒体基因组中特有的ORF,并进行聚合酶链式反应(polymerase chain reaction,PCR)验证、相对表达量分析和生物信息学分析。【结果】D2A和D8A这2个不育系线粒体基因组之间存在2个部分重叠且相邻的倒易位区域。在D2A中发现17个特异的ORF,PCR验证了D2A中存在的6个特异ORF(orf114e、orf121b-1、orf121b-2、orf138b-2、orf186a-2和orf317a-2)。3~4 mm花蕾中orf121b-1和orf121b-2的相对表达量较高。orf114e、orf186a-2和orf317a-2具有典型的跨膜结构域和嵌合基因结构,符合不育基因的部分特征。【结论】D2A和D8A线粒体基因组间存在2个相邻的倒易位区域。D2A中存在6个特异的ORF,其中orf114e、orf186a-2和orf317a-2可能与棉花CMS-D2孢子体败育有关。

Phase separation of S-RNase promotes self-incompatibility in Petunia hybrida

Self-incompatibility(SI)is an intraspecific reproductive barrier widely present in angiosperms.The SI system with the broadest occurrence in angiosperms is based on an S-RNase linked to a cluster of multiple S-locus F-box(SLF)genes found in the Solanaceae,Plantaginaceae,Rosaceae,and Rutaceae.Recent studies reveal that non-self S-RNase is degraded by the Skip Cullin F-box(SCF)SLF-mediated ubiquitin–proteasome system in a collaborative manner in Petunia,but how self-RNase functions largely remains mysterious.Here,we show that S-RNases form S-RNase condensates(SRCs)in the self-pollen tube cytoplasm through phase separation and the disruption of SRC formation breaks SI in self-incompatible Petunia hybrida.We further find that the pistil SI factors of a small asparagine-rich protein HT-B and thioredoxin h together with a reduced state of the pollen tube all promote the expansion of SRCs,which then sequester several actin-binding proteins,including the actin polymerization factor PhABRACL,the actin polymerization activity of which is reduced by S-RNase in vitro.Meanwhile,we find that S-RNase variants lacking condensation ability fail to recruit PhABRACL and are unable to induce actin foci formation required for pollen tube growth inhibition.Taken together,our results demonstrate that phase separation of S-RNase promotes SI response in P.hybrida,revealing a new mode of S-RNase action.

Molecular insights into self-incompatibility systems:From evolution to breeding

Plants have evolved diverse self-incompatibility(SI)systems for outcrossing.Since Darwin’s time,consid-erable progress has been made toward elucidating this unrivaled reproductive innovation.Recent advances in interdisciplinary studies and applications of biotechnology have given rise to major break-throughs in understanding the molecular pathways that lead to SI,particularly the strikingly different SI mechanisms that operate in Solanaceae,Papaveraceae,Brassicaceae,and Primulaceae.These best-un-derstood SI systems,together with discoveries in other"nonmodel"SI taxa such as Poaceae,suggest a complex evolutionary trajectory of SI,with multiple independent origins and frequent and irreversible losses.Extensive exploration of self-/nonself-discrimination signaling cascades has revealed a compre-hensive catalog of male and female identity genes and modifier factors that control SI.Thesefindings also enable the characterization,validation,and manipulation of SI-related factors for crop improvement,helping to address the challenges associated with development of inbred lines.Here,we review current knowledge about the evolution of SI systems,summarize key achievements in the molecular basis of pol-len‒pistil interactions,discuss potential prospects for breeding of SI crops,and raise several unresolved questions that require further investigation.

Identification of S-RNase genotype and analysis of its origin and evolutionary patterns in Malus plants

Identification of the S genotype of Malus plants will greatly promote the discovery of new genes,the cultivation and production of apple,the breeding of new varieties,and the origin and evolution of self-incompatibility in Malus plants.In this experiment,88 Malus germplasm resources,such as Aihuahong,Xishuhaitang,and Reguanzi,were used as materials.Seven gene-specific primer combinations were used in the genotype identification.PCR amplification using leaf DNA produced a single S-RNase gene fragment in all materials.The results revealed that 70 of the identified materials obtained a complete S-RNase genotype,while only one S-RNase gene was found in 18 of them.Through homology comparison and analysis,13 S-RNase genotypes were obtained:S_(1)S_(2)(Aihuahong,etc.),S_(1)S_(28)(Xixian Haitang,etc.),S_(1)S_(51)(Hebei Pingdinghaitang),S_(1)S_(3)(Xiangyangcun Daguo,etc.),S_(2)S_(3)(Zhaiyehaitang,etc.),S_(3)S_(51)(Xishan 1),S_(3)S_(28)(Huangselihaerde,etc.),S_(2)S_(28)(Honghaitang,etc.),S_(4)S_(28)(Bo 11),S_(7)S_(28)(Jiuquan Shaguo),S_(10)S_e(Dongchengguan 13),S_(10)S_(21)(Dongxiangjiao)and S_(3)S_(51)(Xiongyue Haitang).Simultaneously,the frequency of the S gene in the tested materials was analyzed.The findings revealed that different S genes had varying frequencies in Malus resources,as well as varying frequencies between intraspecific and interspecific.S_(3) had the highest frequency of 68.18%,followed by S_(1)(42.04%).In addition,the phylogenetic tree and origin evolution analysis revealed that the S gene differentiation was completed prior to the formation of various apple species,that cultivated species also evolved new S genes,and that the S_(50) gene is the oldest S allele in Malus plants.The S_(1),S_(29),and S_(33) genes in apple-cultivated species,on the other hand,may have originated in M.sieversii,M.hupehensis,and M.kansuensis,respectively.In addition to M.sieversii,M.kansuensis and M.sikkimensis may have also played a role in the origin and evolution of some Chinese apples.

白桫椤GGB途径快速繁殖与不完全组织培养

[目的]优化白桫椤的组织培养技术,可缩短植株繁育周期,进一步提高繁育效率。[方法]本研究以白桫椤的孢子为外植体,研究不同基本培养基对孢子萌发的影响;探讨不同植物生长调节剂对绿色球状体(GGB)诱导和增殖的影响;通过不完全组织培养法,筛选孢子体转化的最佳基质和培养方式。[结果]诱导孢子萌发最佳基质为1/10 MS,萌发率69.55%,10 d可见孢子萌发,在1/2 MS培养基下孢子萌发存在抑制情况;GGB诱导培养基以1/2 MS+NAA 0.2 mg·L^(–1)较适宜,诱导率为92.22%;GGB增殖培养基以1/2 MS+NAA 0.1~0.5 mg·L^(–1)+IBA 0~0.1 mg·L^(–1)较适宜,60 d增殖系数可达6.14;活性炭也有利于GGB增殖,其中1/2 MS+NAA 0.1 mg·L^(–1)+活性炭1.0 g·L^(–1)增殖效果最好,60 d增殖系数可达7.84;因孢子体难以在组培过程中直接获得,通过将GGB团移栽至瓶外基质中能成功诱导出孢子体,最适基质为泥炭∶珍珠岩∶椰糠(2∶1∶1),移栽90 d转化率为43.33%;Knauss不完全组织培养法在白桫椤离体繁殖中的具有可行性,在基质为泥炭∶珍珠岩(1∶1)时,32 d即能成功诱导出孢子体,孢子体转化率高达86.67%。[结论]通过GGB途径可以实现白桫椤的快速增殖,不完全组织培养法能有效提高幼孢子体的转化率,为白桫椤规模化生产育苗提供技术支撑。

Preliminary Analysis of Population Genetic Diversity of Cultivated Laminaria japonica Sporophyte via AFLP Technique

The amplified fragment length polymorphic DNA (AFLP) technique was adopted to estimate the population genetic polymorphism among 30 sporophytes of Laminaria japonica collected from a cultivating farm in Rongcheng,China.Three methods were used for genomic DNA extraction from Laminaria japonica sporophyte and only the products obtained using the improved genomic DNA extraction kit method proved qualified for AFLP analysis.The parameters of the method were optimized.Samples of forty milligrams and the cell lysis time of 120 min were suggested to replace the parameters recommended by the manufacturer.Thirty individuals of Laminaria japonica from the same cultivating site were investigated using one pair of selective primers.A total of 21 loci were obtained and 17 of them were polymorphic.The mean percent age of polymorphic loci of this population was 80.95%.The Nei's gene diversity (H) within this population was 0.3028 and the average Shannon's Information index (I) was 0.4498.A genetic distance matrix among different individuals was constructed as well.Through this study,an applicable AFLP genetic analysis working system for Laminaria japonica sporophyte was established.The results of this research also revealed a high level of genetic diversity within the studied population.

High Frequency Sporophytes Regeneration from the Spore Culture of the Endangered Aquatic Fern <i>Isoetes coreana</i>

Using a mixed culture of megaspores and microspores from I. coreana, we established high frequency sporophyte regeneration system. After 20 days of culturing in MS basal medium, microscopic examination showed significant morphological changes and the microspore released numerous small vesicles into the culture medium. Megaspores also showed dramatic morphological changes during its incubation time in culture. The spore wall was cracked by the expansion of the megaspore (about 2 times increase in diameter). Simultaneously, brown spots were observed on the surface of the megaspores. The frequency of female gametophytes developing from immature megaspores cultured in MS basal liquid medium (pH 7) supplemented with 1 mgl-1 GA3 was 46%. However, these female gametophytes derived from megaspore only culture could not differentiate into sporophytes. The mixed culture of microspores and megaspores resulted in successful sporophyte regeneration. The highest frequency (12.3%) of green sporophyte regeneration from mixed spore culture occurred when the cultures were maintained at 25℃ under cool-white fluorescent light (40 μmol·m-2·s-1) with a 16 h photoperiod. Regenerated sporophytes were transferred to a test tube containing vermiculite and a sand mixture and left there until they had three leaves. After root growth and the fifth leaf had emerged, more than 95% of the regenerated sporophytes were successfully transferred to the soil and grown to mature plants. The sporophyte regeneration system established in this study could be successfully used for the restoration of the endangered aquatic species, I. coreana.

Identification and bioinformatics analysis of micro RNAs from the sporophyte and gametophyte of Pyropia haitanensis

Pyropia haitanensis(T.J.Chang et B.F.Zheng) N.Kikuchi et M.Miyata( Porphyra haitanensis) is an economically important genus that is cultured widely in China.P.haitanensis is cultured on a larger scale than Pyropia yezoensis,making up an important part of the total production of cultivated Pyropia in China.However,the majority of molecular mechanisms underlying the physiological processes of P.haitanensis remain unknown.P.haitanensis could utilize inorganic carbon and the sporophytes of P.haitanensis might possess a PCK-type C 4-like carbon-fixation pathway.To identify micro RNAs and their probable roles in sporophyte and gametophyte development,we constructed and sequenced small RNA libraries from sporophytes and gametophytes of P.haitanensis.Five micro RNAs were identified that shared no sequence homology with known micro RNAs.Our results indicated that P.haitanensis might posses a complex s RNA processing system in which the novel micro RNAs act as important regulators of the development of different generations of P.haitanensis.

基于PGGB途径优化桫椤组织培养繁殖体系研究

为优化桫椤(Alsophila spinulosa)快繁体系,提高其繁殖效率,以桫椤孢子为外植体,通过研究不同生长调节剂对孢子诱导配子体、原叶体绿色球状体(prothallus green globular body,PGGB)诱导、PGGB分化、孢子体生根4个过程的影响,进一步探讨不同基质对桫椤组培苗移栽的成活效果。结果表明,(1)孢子诱导配子体,1/8 MS+0.5 mg/L 6-BA+0.1 mg/L NAA+蔗糖20 g/L+琼脂10 g/L诱导效果最佳,诱导率64.62%,诱导天数23 d。(2)PGGB诱导,1/2 MS+0.3 mg/L 6-BA+0.4 mg/L NAA+蔗糖30 g/L+琼脂6 g/L诱导率达100%,PGGB鲜重1.13 g,增殖倍数11.04,直径2.01 cm。(3)PGGB分化,在1/2 MS+0.3 mg/L KT+0.4 mg/L IBA+蔗糖30 g/L+琼脂6 g/L的分化效果最佳,分化率92.12%,PGGB平均分化芽数41.67个。(4)孢子体生根,孢子体在1/2 MS+1.0 mg/L IBA+蔗糖30 g/L+琼脂6 g/L中的生根率100%。(5)炼苗,组培苗移栽在基质(红壤∶腐殖土∶泥炭土=2∶1∶1)中的成活率为96.3%。桫椤PGGB诱导及其再生体系的建立受植物生长调节剂影响,且基质对桫椤组培苗的成活率差异显著。研究成功构建了1个高效的桫椤繁殖再生体系,为进一步探究桫椤体外培养发育机制、新品种、规模生产及应用提供技术支持。

High-quality Fagopyrum esculentum genome provides insights into the flavonoid accumulation among different tissues and self-incompatibility

Common buckwheat(Fagopyrum esculentum)and Tartary buckwheat(Fagopyrum tataricum),the two most widely cultivated buckwheat species,differ greatly in flavonoid content and reproductive mode.Here,we report the first high-quality and chromosome-level genome assembly of common buckwheat with 1.2 Gb.Comparative genomic analysis revealed that common buckwheat underwent a burst of long terminal repeat retrotransposons insertion accompanied by numerous large chromosome rearrangements after divergence from Tartary buckwheat.Moreover,multiple gene families involved in stress tolerance and flavonoid biosynthesis such as multidrug and toxic compound extrusion(MATE)and chalcone synthase(CHS)underwent significant expansion in buckwheat,especially in common buckwheat.Integrated multi-omics analysis identified high expression of catechin biosynthesis-related genes in flower and seed in common buckwheat and high expression of rutin biosynthesis-related genes in seed in Tartary buckwheat as being important for the differences in flavonoid type and content between these buckwheat species.We also identified a candidate key rutindegrading enzyme gene(Ft8.2377)that was highly expressed in Tartary buckwheat seed.In addition,we identified a haplotype-resolved candidate locus containing many genes reportedly associated with the development of flower and pollen,which was potentially related to self-incompatibility in common buckwheat.Our study provides important resources facilitating future functional genomics-related research of flavonoid biosynthesis and selfincompatibility in buckwheat.

金毛狗脊原叶体增殖和孢子体转化条件的优化

为探究不同浓度的无机盐、蔗糖、KT、NAA和6-BA等对金毛狗脊原叶体增殖和孢子体转化的影响,采用正交设计实验方法,设置5因素4水平正交试验,筛选金毛狗脊原叶体增殖和孢子体转化的最佳培养基。结果表明,原叶体增殖最佳培养基为1/2MS+2%蔗糖+0.1 mg/L NAA+0.3 mg/L 6-BA+0.1 mg/L KT。孢子体转化最佳培养基为1/4MS+1%蔗糖+0.5 mg/L KT+0.1 mg/L NAA。

裙带菜配子体与孢子体的附生微生物群落组成分析

裙带菜(Undaria pinnatifida)是一种重要的大型褐藻,具有较高的经济和食用价值。藻类的附生微生物既能通过代谢产物调控宿主藻类的生长发育,特定条件下又可能导致病害。了解裙带菜附生微生物群落组成对研究裙带菜与附生微生物间的相互作用、种质资源的有效保存以及防治藻类病害等有重要意义。现有研究大多集中于海带和紫菜,关于裙带菜的附生微生物,特别是不同生活史的对比研究还很少。本研究通过16S rRNA基因高通量测序发现,裙带菜配子体和孢子体的附生细菌群落组成有明显差异,配子体样品中的细菌群落丰度和多样性均大于孢子体。配子体中变形菌门(Proteobacteria)(66.67%)为第一优势菌门,其次为拟杆菌门(Bacteroidetes)(13.48%)和蓝细菌门(Cyanobacteria)(11.13%),α-变形菌纲(Alphaproteobacteria)(34.58%)为第一优势菌纲,其次为γ-变形菌纲(Gammaproteobacteria)(31.01%);而孢子体中蓝细菌门(95.67%)占绝对优势,其次为放线菌门(Actinobacteria)(1.65%)和厚壁菌门(Firmicutes)(1.48%)。裙带菜样品经18S rRNA基因测序检测出链形植物(Streptophyta)、纤毛虫门(Intramacronucleata)、担子菌门(Basidiomycota)、顶复亚门(Apicomplexa)、节肢动物门(Arthropoda)、硅藻门(Bacillariophyta)、脊索动物门(Chordata)、腹毛动物门(Gastrotricha)、子囊菌门(Ascomycota)和毛霉菌门(Mucoromycota),其中,担子菌门、子囊菌门和毛霉菌门属于真菌,孢子体的真核微生物群落丰度大于配子体。本研究确定了裙带菜配子体和孢子体附生微生物群落组成以及不同细菌和真核微生物的相对丰度,结果表明,2个世代之间存在显著差异,为后续研究藻类宿主与微生物之间的相互作用、提高海带目褐藻种质保存技术提供了基础的数据支持。

钙离子胁迫对槲蕨孢子体叶的影响

为解析钙离子胁迫对槲蕨孢子体叶片生长的影响,以两年生槲蕨孢子体叶为试验材料,研究了0、600、1200 mmol/L CaCl2处理对槲蕨孢子体叶脯氨酸含量、甜菜碱含量、电导率、超氧阴离子含量、过氧化氢含量、酶活性的影响。结果表明,槲蕨孢子体叶的脯氨酸含量、甜菜碱含量随着钙离子浓度的增大而逐渐升高,电导率、超氧阴离子含量和过氧化氢含量随着钙离子浓度的增大而增加,抗坏血酸过氧化物酶、单脱氢抗坏血酸还原酶、脱氢抗坏血酸还原酶和谷胱甘肽还原酶活性随着钙离子浓度的增大而增强。由此表明,钙离子浓度在1200 mmol/L以下时主要产生渗透胁迫作用。