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1. chinaXiv:202206.00189 [pdf]

OsIMA1 增强水稻对镉逆境的适应性

彭凤; 路承凯; 梁岗
Subjects: Biology >> Botany >> Applied botany

铁(Fe)是植物生长发育所必需的营养元素而镉(Cd)是对植物有害的元素,且植 物对 Fe 和 Cd 的吸收存在拮抗作用。OsIMA 是一类正调控水稻 Fe 吸收的一类小肽,其过表 达可以促进 Fe 的积累。为探究 OsIMA 是否参与水稻对 Cd 胁迫的适应性,该研究以水稻为 研究材料,利用荧光定量PCR 分析了OsIMA 基因的表达水平,通过遗传转化和CRISPR/Cas9 基因编辑技术构建了 OsIMA1 过表达植物和 ima1 突变体植物,评估了 OsIMA1 过表达和突 变体植物在 Cd 逆境条件下的株高,并用利用电联耦合等离子体质谱法测量了根和地上部的 Fe 和 Cd 含量。结果表明:(1)Cd 处理后,OsIMA1 和 OsIMA2 的转录水平上调。(2)OsIMA1 过表达植物比野生型植物对 Cd 胁迫更耐受。(3)ima1 功能缺失突变体比野生型植物对 Cd 胁迫更敏感。(4)Cd 含量检测发现,OsIMA1 过表达植株根系的 Cd 含量较高,而 ima1 突 变体植株地上部的 Cd 含量较高。综上所述,OsIMA1 通过限制 Cd 从根向地上部的转运以 增强水稻对 Cd 逆境的适应能力,该研究为定向培育耐 Cd 作物提供了理论依据。

submitted time 2022-06-29 Cooperative journals:《广西植物》 Hits13Downloads3 Comment 0

2. chinaXiv:202206.00091 [pdf]

On kannemeyeriiform dicynodonts from the Shaanbeikannemeyeria Assemblage Zone of the Ordos Basin, China

LIU Jun
Subjects: Biology >> Zoology

Shaanbeikannemeyeria is a common tetrapod from the lower part of the Ermaying Formation of the Ordos Basin, China. There are taxonomical questions surrounding this genus, such as the validity of the genus, and how many species are included within it. Several specimens have been collected since 1978. Shaanbeikannemeyeria first appeared from the top of the Heshanggou Formation. These specimens are described to clarify the diagnostic characters, the individual variations and the phylogenetic position of Shaanbeikannemeyeria. Only one species, S. xilougouensis, is recognized. It is characterized by the following autapomorphies: occiput strongly inclined relative to the palate such that the skull is much shorter basally than dorsally, sword tip-like premaxillary posterodorsal processes, tall and dorsally-convex cutting blade on the medial edge of the dorsal surface of the dentary, reflected lamina with a separated posteroventral process, and 15 dorsal vertebrae. This species shows variations on the cranial morphology, such as the occiput height relative to the width, the snout tip (sharp or obtuse), the shape of the orbital portion of the zygomatic arch, and the shape of caniniform process. Some variations could be ontogenetically related, such as the development of the caniniform process and tusk, the posterior extension of the maxilla on the zygomatic arch, the distance between the frontal and the premaxilla, the intertemporal bar width, and the exposing degree of the parietals. Based on postcranial bones, the second dicynodont genus (possibly Parakannemeyeria) is present in the lower Ermaying Formation.

submitted time 2022-06-07 Cooperative journals:《古脊椎动物学报》 Hits614Downloads196 Comment 0

3. chinaXiv:202206.00103 [pdf]

拟南芥bHLH Ib 转录因子调控FIT 的转录

杨钰洁; 梁岗
Subjects: Biology >> Botany >> Applied botany

FIT 是调控拟南芥铁稳态的一个关键调控因子,它在转录水平受到缺铁诱导,但是背 后的调控机制还不甚清楚。该研究以拟南芥bHLH38 和FIT 的单、双过表达植物及 bHLH Ib 四突变体为研究材料,进行了缺铁处理实验,并通过定量 PCR 分析了FIT 的转录水平。结果 表明:(1)在铁充足时,bHLH38 过表达植物中FIT 的转录水平显著高于其在野生型中水平; (2)在 bHLH Ib 四突变体里FIT 的转录水平不受缺铁诱导;(3)FIT 单过表达不能激活内 源FIT 的转录,但bHLH38 和FIT 的双过表达则可以激活内源FIT 的转录;(4)在缺铁条件 下,所有植物中FIT 的转录水平均与野生型中的FIT 水平无明显差异。基于以上结果,该研 究认为 bHLH Ib 转录因子是缺铁诱导FIT 转录的必要条件,而非充分条件。

submitted time 2022-06-07 Cooperative journals:《广西植物》 Hits96Downloads71 Comment 0

4. chinaXiv:202205.00151 [pdf]

云南被子植物菊类分支的系统发育多样性及其分布格局

周韩洁; 杨入瑄; 李嵘
Subjects: Biology >> Botany >> Applied botany

全球气候变化与人为活动等因素导致的生物多样性丧失,引起了全球各界对生物多样性保护的高度关注。传统生物多样性保护主要对物种、特有种、受威胁物种的种类组成及其分布模式开展研究,忽视了进化历史在生物多样性保护中的作用。云南是全球生物多样性热点地区的交汇区,生物多样性的保护历来受到广泛关注,为了更好地探讨云南生物多样性的保护措施,该研究以云南被子植物菊类分支物种为研究对象,基于物种间的演化关系,结合其地理分布,从进化历史的角度探讨物种、特有种、受威胁物种的种类组成及系统发育组成的分布格局,并整合自然保护地的空间分布,识别生物多样性的重点保护区域。结果表明:云南被子植物菊类分支的物种、特有种及受威胁物种的物种密度与系统发育多样性均显著正相关;由南向北,标准化系统发育多样性逐渐降低;云南南部、东南部、西北部是云南被子植物菊类分支的重点保护区域,加强这些区域的保护,将最大化地保护生物多样性的进化历史和进化潜能。由此可见,融合进化历史信息的植物多样性格局分析不仅有助于更加深入地理解植物多样性的形成与演变,也为生物多样性保护策略的制定提供更多的思路。

submitted time 2022-05-21 Cooperative journals:《广西植物》 Hits455Downloads253 Comment 0

5. chinaXiv:202204.00119 [pdf]

Xitunaspis, a new eugaleaspid fish (Eugaleaspiformes, Galeaspida) from the Lower Devonian of Qujing, Yunnan

SUN Hao-Ran; GAI Zhi-Kun; CAI Jia-Chen; LI Qiang; ZHU Min; ZHAO Wen-Jin
Subjects: Biology >> Zoology

A new genus and species of the family Eugaleaspidae (Eugaleaspiformes, Galeaspida), Xitunaspis magnus gen. et sp. nov., is described from the Lower Devonian Xitun Formation in Qujing, Yunnan Province, China. The new genus displays the diagnostic characters of the Eugaleaspidae, including a slit-like median dorsal opening, no inner cornual process, developed median dorsal canals, and only three pairs of lateral transverse canals extending from lateral dorsal canals. Different from the other eugaleaspids, X. magnus possesses a large headshield with thick dermal bone and a more plesiomorphic sensory canal system. The phylogenetic analysis of the Galeaspida reveals that Xitunaspis clusters with Dunyu and Eugaleaspis to form a monophyletic clade Eugaleaspidae Liu, 1965, and has a closer relationship with Dunyu than Eugaleaspis by sharing the thick dermal bone of the headshield. The new finding represents the first convincing fossil record of the Eugaleaspiformes in the middle Lochkovian Xitun Formation and adds to our knowledge about the morphology of eugaleaspiforms and the evolutionary pattern of the sensory canal system in the Eugaleaspiformes and even Galeaspida.

submitted time 2022-04-16 Cooperative journals:《古脊椎动物学报》 Hits3101Downloads430 Comment 0

6. chinaXiv:202204.00120 [pdf]

New fossils of small and medium-sized bovids from the Early Pleistocene Site of Shanshenmiaozui in Nihewan Basin, North China

TONG Hao-Wen; ZHANG Bei; CHEN Xi; WANG Xiao-Min
Subjects: Biology >> Zoology

Shanshenmiaozui site in Nihewan Basin in North China is a recently discovered Early Pleistocene site which yields rich and diverse mammalian fossils. In the fauna, the small and medium-sized bovid fossils are well represented and can be referred to the following taxa: Spirocerus wongi, Gazella sinensis, Ovis shantungensis and Megalovis piveteaui respectively, among which G. sinensis is the dominate species. S. wongi and G. sinensis are mainly represented by horn-cores and partial skull bones as well as mandibles; in addition, metacarpal and/or metatarsal bones were also recognized for all of the four species. The horn-cores are easy to be identified to the species level, while the dentitions and the postcranial bones underwent a series of examinations and comparisons before getting properly determined and referred to the most approximate taxa. Among the postcranial bones, the metapodials, especially to the metacarpal bones special attentions were paid, which are crucial not only for taxonomic identification, but also for phylogenetic and paleoecological reconstructions; the previously misidentified metapodial specimens in Nihewan fauna were reconsidered in this paper. In the SSMZ fauna, the bovid guild is dominated by Gazella and Bison, which indicates steppe was the most important biome in Nihewan Basin during Early Pleistocene.

submitted time 2022-04-16 Cooperative journals:《古脊椎动物学报》 Hits2669Downloads400 Comment 0

7. chinaXiv:202204.00121 [pdf]

Attributing “Gomphotherium shensiense” to Platybelodon tongxinensis, and a new species of Platybelodon from the latest Middle Miocene

WANG Shi-Qi; LI Chun-Xiao
Subjects: Biology >> Zoology

Platybelodon is the predominant proboscidean of northern China’s Middle Miocene. However, the cranial and cheek tooth morphologies are not clearly diagnosed. In particular, the differential diagnoses between Platybelodon and Gomphotherium have not been comprehensively examined. Here we restudied the cranium previously identified as Gomphotherium shensiense. The upper tusks lack an enamel band, the rostrum is long and narrow, the facial part is rostrally positioned, and a large “prenasal slope” is present. These characters are distinct from those of any species of Gomphotherium, but fit well with some primitive species of Platybelodon, i.e., P. tongxinensis and P. danovi. The molars are also close to the type specimen of P. tongxinensis in the tetralophodont M3 with mesiodistally wide interlophs, curved outline, and a tendency of cementodonty. In this article, we synonymized Gomphotherium shensiense with P. tongxinensis. Moreover, we recognized a new species, Platybelodon tetralophus, from the P. grangeri material collected by the AMHN expedition in Tunggur region. Platybelodon tetralophus differs from P. grangeri and the other species in the tetralophodont M2 and m2, representing the most derived species within Platybelodon. It has only occurred in the uppermost horizon of the Tunggur Formation, i.e., the Tamuqin Fauna (Platybelodon Quarry and Wolf Camp Quarry of AMHN). This work is a comprehensive amending of the genus Platybelodon.

submitted time 2022-04-16 Cooperative journals:《古脊椎动物学报》 Hits2975Downloads361 Comment 0

8. chinaXiv:202203.00050 [pdf]

基于分子与形态证据的傣药“傣百解”基原考证

李金月; 谭运洪; 李海涛; 岩罕单; 龚燕雄; 肖云学; 郁文彬
Subjects: Biology >> Botany >> Applied botany

“傣百解”是傣医常用的一种解药,其基原植物最早记录是夹竹桃科苦绳(Dregea sinensis),后 来被鉴定是夹竹桃科通光散(Marsdenia tenacissima)。为了进一步澄清“傣百解”的基原植物,该研究 结合形态与分子证据对“傣百解”基原植物及近缘种进行了整合分析。结果表明:(1) 利用三个DNA 片段(psbD-trnT, trnL-trnF, ITS) 重建牛奶菜属(Marsdenia)及其它牛奶菜族物种的系统发育关系显示, “傣百解”样品与通光散样品构成一个独立的单系分支,并与灵药牛奶菜(Marsdenia cavaleriei)构成姐 妹类群。(2) 结合形态性状与模式标本的对比分析发现“傣百解”基原植物与通光散模式标本基本一致, 而其形态特征与姐妹种灵药牛奶菜存在明显差异。(3)进一步确定了“傣百解”的基原植物是通光散, 其叶形态与花部性状差异可作为区分通光散和灵药牛奶菜的重要特征。该研究通过整合形态特征与分 子证据完成了对“傣百解”的正本清源,可用于市场药材的快速准确鉴定,也为“傣百解”今后的开 发利用奠定了基础。

submitted time 2022-03-18 Cooperative journals:《广西植物》 Hits539Downloads335 Comment 0

9. chinaXiv:202201.00059 [pdf]

Reappraisal of the largest ctenochasmatid Moganopterus zhuiana L?et al., 2012

GAO Dian-Song; JIANG Shun-Xing; XU Li1 CHENG Xin; YANG Li-Li; JIA Song-Hai; WANG Xiao-Lin
Subjects: Biology >> Zoology

Moganopterus zhuiana L?et al. 2012 was erected as a member of the Boreopteridae, which was questioned by different researchers shortly after the publication. Although the new assignment to the Ctenochasmatidae is widely accepted by pterosaur researchers, some characteristics still require a detailed description. Here, the holotype of this taxon is restudied, and some ambiguous characteristics are re-identified. The diagnosis of this taxon has been revised as the following: a large ctenochasmatid pterosaur, which can be distinguished from other members of this clade by a single autapomorphy: an elongated rod-like parietal crest that extends posterodorsally, forming an angle of about 15?with the ventral margin of the skull. This taxon can be further distinguished from other ctenochasmatids on the basis of the following combination of characteristics: straight occlusal surfaces of the upper and low jaws; presence of a low premaxillary crest confined anterior to the nasoantorbital fenestra; rostrum about two thirds of the skull length; nasoantorbital fenestra occupying slightly more than 20% of the skull length; about 100 slender teeth; and a mid-cervical length/width ratio of about 7. The wingspan of M. zhuiana has been re-estimated according to a simple regression equation for wingspan versus skull length in ctenochasmatids. It confirms that M. zhuiana, although smaller than previous thought, is still the largest known ctenochasmatid. When comparing the sizes of ctenochasmatids in the Jurassic and Cretaceous, ctenochasmatids showed a rough tendency to increase their sizes.

submitted time 2022-01-19 Cooperative journals:《古脊椎动物学报》 Hits3530Downloads557 Comment 0

10. chinaXiv:202112.00140 [pdf]

海人树的生态生物学特性

周婉敏; 林若宜; 刘楠; 任海; 徐贝贝; 简曙光
Subjects: Biology >> Botany >> Applied botany

海人树(Suriana maritima)是海人树科的一种滨海观赏植物,在中国目前仅分布于南海诸 岛。该文以西沙群岛自然生长的海人树为研究对象,通过调查、采样,分析测定其茎杆及其叶片 的形态解剖结构、叶片的抗氧化酶活性和抗逆渗透物质含量,以及叶片与生长土壤的营养元素含 量等生态生物学特性,旨在为其保护及开发利用提供理论依据。结果表明:海人树的叶片小而厚, 角质层明显,栅栏组织发达,气孔密度小(8.64 n·mm-2),易于维持体内水分,能很好适应干旱 和高盐碱的环境;叶片的叶绿素含量低(0.76 mg·g-1),总抗氧化能力高(589.50 U·g-1),脯氨 酸含量高(1 123.64 μg·g-1),表明海人树光合利用效率高,抗氧化能力强。海人树根际土壤的养 分含量低,但叶片有机碳、氮和磷含量较高(分别为 490.27、18.10 和 3.81 g·kg-1),表明海人树的 土壤养分利用效率高,对贫瘠的土壤具有良好的适应能力。因此,海人树对强光、干旱、高盐碱 和土壤贫瘠的热带珊瑚岛环境具有良好的适应能力,可作为热带珊瑚岛植被恢复和园林绿化的工 具种。

submitted time 2021-12-19 Cooperative journals:《广西植物》 Hits3819Downloads420 Comment 0

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