毛竹基因组大小测定

毛竹(Phyllostachys edulis)属禾本科(Poaceae)竹亚科(Bambusoideae)刚竹属(Phyllostachys), 是我国分布和栽培面积最大的经济竹种, 有着广泛的开发前景。本实验以水稻(Oryza sativa)为内标, 用流式细胞仪对水稻和竹子样品的PI发射荧光强度进行测定, 通过比较水稻与毛竹样品峰值的倍数关系, 计算出毛竹的基因组大小。对24组样品进行重复测试, 测得毛竹基因组大小为 2 075.025±13.08 Mb, 即2 C DNA含量为4.24 pg(以1 pg DNA = 0.978×109 bp计算)。毛竹基因组大小测定为毛竹基因组文库的建立及其基因组学研究奠定了重要基础。     

毛竹基因组大小测定

毛竹（Phyllostachys edulis）属禾本科（Poaceae）竹亚科（Bambusoideae）刚竹属（Phyllostachys）,是我国分布和栽培面积最大的经济竹种,有着广泛的开发前景。本实验以水稻（Oryza sativa）为内标,用流式细胞仪对水稻和竹子样品的PI发射荧光强度进行测定,通过比较水稻与毛竹样品峰值的倍数关系,计算出毛竹的基因组大小。对24组样品进行重复测试,测得毛竹基因组大小为2075.025±13.08Mb,即2C DNA含量为4.24pg（以1pg DNA=0.978×10^9bp计算）。毛竹基因组大小测定为毛竹基因组文库的建立及其基因组学研究奠定了重要基础。     

毛竹扩展蛋白基因的鉴定及其表达分析

为全面了解毛竹中扩展蛋白的分子特征和表达模式,本研究利用生物信息学方法在毛竹基因组中共鉴定出43个扩展蛋白基因家族成员,属于4个亚家族（EXPA、EXPB、EXLA和EXLB）,分别包含18、17、7和1个成员,分布在37个Scaffold上。除PeEXPA1没有内含子和PeEXLB1含有11个内含子外,其它毛竹扩展蛋白基因的内含子为1~5个。毛竹扩展蛋白基因编码蛋白长度为91~508个氨基酸,所有的氨基酸都具有高频密码子,大部分蛋白为碱性亲水性蛋白。大部分毛竹扩展蛋白二级结构中β转角占比例最少,而β折叠占比例最大,各亚家族多数成员具有类似的三级结构。qRT-PCR结果表明,18个EXPA亚家族成员在不同组织表达存在明显差异,除PeEXPA2、PeEXPA6外其它基因表达的最高值均出现在叶片中,表明它们可能在叶片生长过程中发挥着重要作用。     

Genome-Wide Identification,Characterization, and Stress-Responsive Expression Profiling of Genes Encoding LEA (Late Embryogenesis Abundant) Proteins in Moso Bamboo (Phyllostachys edulis)

Late embryogenesis abundant (LEA) proteins have been identified in a wide range of organisms and are believed to play a role in the adaptation of plants to stress conditions. In this study, we performed genome-wide identification of LEA proteins and their coding genes in Moso bamboo (Phyllostachys edulis) of Poaceae. A total of 23 genes encoding LEA proteins (PeLEAs) were found in P. edulis that could be classified to six groups based on Pfam protein family and homologous analysis. Further in silico analyses of the structures, gene amount, and biochemical characteristics were conducted and compared with those of O. sativa (OsLEAs), B. distachyon (BdLEAs), Z. mays (ZmLEAs), S. bicolor (SbLEAs), Arabidopsis, and Populus trichocarpa. The less number of PeLEAs was found. Evolutionary analysis revealed orthologous relationship and colinearity between P. edulis, O. sativa, B. distachyon, Z. mays, and S. bicolor. Analyses of the non-synonymous (Ka) and synonymous (Ks)substitution rates and their ratios indicated that the duplication of PeLEAs may have occurred around 18.8 million years ago (MYA), and divergence time of LEA family among the P. edulis-O. sativa and P. edulis–B. distachyon, P. edulis-S. bicolor, and P. edulis-Z. mays was approximately 30 MYA, 36 MYA, 48 MYA, and 53 MYA, respectively. Almost all PeLEAs contain ABA- and (or) stress-responsive regulatory elements. Further RNA-seq analysis revealed approximately 78% of PeLEAs could be up-regulated by dehydration and cold stresses. The present study makes insights into the LEA family in P. edulis and provides inventory of stress-responsive genes for further functional validation and transgenic research aiming to plant genetic improvement of abiotic stress tolerance.     

A Pilot Study on Internode Elongation in a Paleotropical Bamboo,Dendrocalamus latiflorus (Poaceae: Bambusoideae)

The rapid growth of bamboo culms at the juvenile stage is still an unresolved scientific issue in grass biology. In this study, we selected the eighth node as the standard node to investigate internode development in the paleotropical bamboo species, Dendrocalamus latiflorus. An elongation curve and anatomical features of the eighth internode were determined using statistical methods and a paraffin section technique, respectively. Internode elongation was found to show a “slow fast” trend. During early stages of internode development, most cells divided quickly, but then gradually stopped dividing before elongating in a top down orientation between the nodes. Finally, cells forming the internode stopped elongating and became mature. This is the first report on internode development of a large sized paleotropical bamboo species, and should promote further research on rapid growth of bamboo shoots.     

麻竹节间伸长过程的初步研究

竹子秆茎的快速生长是禾本科生物学的一个未解之谜,而秆茎的生长又是以节间为单位进行的。本研究以第8节为标准节,利用统计学及石蜡切片的方法,获得了麻竹的节间伸长曲线以及节间组织发育的形态解剖信息。麻竹节间的伸长呈现“慢-快”的生长趋势,早期节间以细胞分裂为主,然后节间由上到下逐渐进入细胞伸长阶段,最后节间停止伸长进入成熟生长阶段。本研究为大型丛生竹节间发育的研究提供了基础数据,有助于推动对竹子笋株快速生长机制的研究。     

毛竹7个COBL基因的分子特征及表达分析

COBL家族基因编码糖基磷脂酰基醇锚定蛋白,主要参与调控植物细胞壁纤维素的含量和细胞的定向伸长.研究毛竹COBL基因的分子特征和表达模式,对揭示其材性快速形成机制具有重要意义.利用生物信息学方法对毛竹COBL家族成员进行全基因组分析,共鉴定出7个具有完整保守结构域的COBL家族基因成员(PeCOBL1～PeCOBL7)...     

Diversity of Culturable Bacteria Isolated from Root Domains of Moso Bamboo (Phyllostachys edulis)

The distribution of culturable bacteria in the rhizosphere, rhizoplane, and interior root tissues of moso bamboo plants was investigated in this study. Of the 182 isolates showing different colony characteristics on Luria–Bertani and King B plates, 56 operational taxonomic units of 22 genera were identified by 16S ribosomal RNA gene sequence analysis. The majority of root endophytic bacteria were Proteobacteria (67.5%), while the majority of rhizospheric and rhizoplane bacteria were Firmicutes (66.3% and 70.4%, respectively). The most common genus in both the rhizosphere and on the rhizoplane was Bacillus (42.4% and 44.4%, respectively), while Burkholderia was the most common genus inside the roots, comprising 35.0% of the isolates from this root domain. The endophytic bacterial community was less diverse than the rhizoplane and rhizospheric bacterial communities. Members of Lysinibacillus, Bacillus, and Burkholderia were found in all three root domains, whereas many isolates were found in only a single domain. Our results show that the population diversity of culturable bacteria is abundant in the root domains of moso bamboo plants and that obvious differences exist among the rhizospheric, rhizoplane, and endophytic bacterial communities.     

NaCl胁迫对毛竹叶片的电阻抗图谱参数及膜透性的影响

以NaCl胁迫下毛竹（Phyllostachys edulis）实生苗叶片为材料,测定其电阻抗图谱参数和膜透性的变化,通过膜透性与电阻抗图谱参数间的相关性,来证明电阻抗图谱法研究竹子受胁迫程度的有效性。结果表明：随着盐浓度的升高,胞外电阻、胞内电阻和弛豫时间呈现先减小、后增加、再减小的特征,而弛豫时间分布系数表现恰好相反;叶片细胞膜相对透性逐渐增大,脯氨酸的含量先逐渐增大,然后减小。相关分析表明：胞内电阻、胞外电阻、弛豫时间与脯氨酸含量呈极显著负相关（p〈0.01）;胞外电阻、弛豫时间与膜相对透性呈显著负相关（p〈0.05）。电阻抗图谱参数能够有效地表示毛竹受NaCl胁迫的程度,电阻抗图谱法将是竹子逆境胁迫研究的一种有效方法。     

Correction to: Genome-wide Identification of Trihelix Genes in Moso Bamboo (Phyllostachys edulis) and Their Expression in Response to Abiotic Stress

Journal of Plant Growth Regulation - The original version of this article unfortunately contained an error in Funding section. The authors would like to correct the error with this erratum.