春小麦胚芽伸长过程中渗透调节与能量代谢

本文用PEG模拟水分亏缺对春小麦红芒麦和绵阳11号胚芽伸长过程中生长、膨压、渗透势、水势和渗透调节能力与ATP含量、能荷变化及能量代谢间的关系进行了研究。结果表明,通过降低能荷,改变分解代谢与合成代谢的比率,使渗透调节物质积累,增加了幼苗的吸水能力,从而使其在一定的ATP能量水平上维持缓慢生长;抗旱品种红芒麦在水分亏缺下成苗速率较快,能保持一定的ATP能量水平和能荷值,渗透调节和吸水能力都比较强。     

Embryos,polyps and medusae of the Early Cambrian scyphozoan Olivooides

The Early Cambrian organism Olivooides is known from both embryonic and post-embryonic stages and, consequently, it has the potential to yield vital insights into developmental evolution at the time that animal body plans were established. However, this potential can only be realized if the phylogenetic relationships of Olivooides can be constrained. The affinities of Olivooides have proved controversial because of the lack of knowledge of the internal anatomy and the limited range of developmental stages known. Here, we describe rare embryonic specimens in which internal anatomical features are preserved. We also present a fuller sequence of fossilized developmental stages of Olivooides, including associated specimens that we interpret as budding ephyrae (juvenile medusae), all of which display a clear pentaradial symmetry. Within the framework of a cnidarian interpretation, the new data serve to pinpoint the phylogenetic position of Olivooides to the scyphozoan stem group. Hypotheses about scalidophoran or echinoderm affinities of Olivooides can be rejected.     

Water and Nutrient Use Efficiency in Diploid, Tetraploid and Hexaploid Wheats

Three diploid (Triticum boeoticum, AA; Aegilops speltoides, BB and Ae. tauschii, DD), two tetraplold (T. dlcoccoides,AABB and T. dicoccon, AABB) and one hexaploid (T. vulgare, AABBDD) varieties of wheat, which are very important in the evolution of wheat were chosen in this study. A pot experiment was carried out on the wheat under different water and nutrient conditions (i) to understand the differences in biomass, yield, water use efficiency (WUE), and nutrient (N, P and K) use efficiency (uptake and utilization efficiency) among ploldles in the evolution of wheat; (ii) to clarify the effect of water and nutrient conditions on water and nutrient use efficiency; and (iii) to assess the relationship of water and nutrient use efficiency in the evolution of wheat. Our results showed that from diploid to tetraploid then to hexaploid during the evolution of wheat, both root biomass and above-ground biomass increased initially and then decreased. Water consumption for transpiration decreased remarkably, correlating with the decline of the growth period, while grain yield, harvest index, WUE, N, P and K uptake efficiency, and N, P and K utilization efficiency increased significantly. Grain yield, harvest index and WUE decreased in the same order: T.vulgare ＞ T. dicoccon ＞ T. dicoccoides ＞ Ae. tauschii ＞ Ae. speltoides ＞ T. boeoticum. Water stress significantly decreased root biomass, above-ground biomass, yield, and water consumption for transpiration by 47-52%, butremarkably increased WUE. Increasing the nutrient supply increased wheat above-ground biomass, grain yield,harvest index, water consumption for transpiration and WUE under different water levels, but reduced root biomass under drought conditions. Generally, water stress and low nutrient supply resulted in the lower nutrientuptake efficiency of wheat. However, water and nutrient application had no significant effects on nutrient utilization efficiency, suggesting that wheat nutrient utilization efficiency is mainly controlled by genotypes. Compared to theother two diploid wheats, Ae. squarrosa (DD) had significant higher WUE and nutrient utilization efficiency, Indicating that the D genome may carry genes controlling high efficient utilization of water and nutrient. Significant relationships were found between WUE and N, P and K utilization efficiency.     

A new metabolite with a new substitution pattern from the seeds of the Chinese Yew, Taxus mairei

A new taxoid metabolite with a new substitution pattern was isolated from the methanol extract of the seeds of Taxus mairei, and its structure was established as 5alpha,15-dihydroxy-7beta,9alpha-diacetoxy-11(15-->1)abeo-taxa-4(20),11-dien-13-one (1) on the basis of spectral analysis including (1)H- and (13)C-NMR, HMQC, HMBC, NOESY, and confirmed by HR-FAB mass spectrometry.     

LUBAC regulates ciliogenesis by promoting CP110 removal from the mother centriole

Primary cilia transduce diverse signals in embryonic development and adult tissues. Defective ciliogenesis results in a series of human disorders collectively known as ciliopathies. The CP110–CEP97 complex removal from the mother centriole is an early critical step for ciliogenesis, but the underlying mechanism for this step remains largely obscure. Here, we reveal that the linear ubiquitin chain assembly complex (LUBAC) plays an essential role in ciliogenesis by targeting the CP110–CEP97 complex. LUBAC specifically generates linear ubiquitin chains on CP110, which is required for CP110 removal from the mother centriole in ciliogenesis. We further identify that a pre-mRNA splicing factor, PRPF8, at the distal end of the mother centriole acts as the receptor of the linear ubiquitin chains to facilitate CP110 removal at the initial stage of ciliogenesis. Thus, our study reveals a direct mechanism of regulating CP110 removal in ciliogenesis and implicates the E3 ligase LUBAC as a potential therapy target of cilia-associated diseases, including ciliopathies and cancers.     

大额牛产犊行为观察

采用直接观察法对大额牛(Bos frontalis)的产前离群与产后带犊归群、分娩等产犊行为进行了观察。结果表明,(1)野外观察17头临产母牛中,76.47%(13头)的个体在产前(11.23±7.14)d离开社群独行觅食,寻找分娩场所;分娩地点多选择在靠近溪河、地势较高、食物丰富、光照好、地面相对平坦的草地、林边或林中。母牛野外产犊后带犊归群的时间为产后(5.57±2.64)d。(2)在设围栏的人工草地上放牧条件下对6头母牛分娩行为观察表明,产前24～12 h母牛的警觉巡视行为明显增多;产前12～5h表现为烦燥不安和频繁爬跨;产前3～1 h领地行为明显,对分娩地点4～6 m2内长势较高的牧草等进行清理,为新生犊牛行动清除障碍;分娩时间为6:00～18:00时,其中在6:00～7:00时分娩的占66.67%(4/6);母牛从卧地进入分娩至犊牛产出期间起卧(7.00±6.00)次,从卧地到犊牛完全产出需(25.00±5.00)min,胎衣排出的时间为产后(5.64±1.80)h;犊牛(n=6,♂1+♀5)初生体重为(16.46±2.56)kg,母牛无难产现象;母牛对犊牛能及时舔饰,定时授乳和用心守护。犊牛从产出至第一次站稳需(52.70±29.69)min,第一次站稳到吮吸初乳需(38.7±29.14)min,第一次吃初乳到向周边活动需(61.33±1.53)min。     

利用固相微萃取技术分析锈色粒肩天牛幼虫虫粪所含的挥发物成分

花绒寄甲Dastarcus helophoroides (Fairmaire)成虫主要利用天牛幼虫蛀食树木时排出的虫粪所释放的挥发性化合物找到寄主所在的微栖境.本试验分别应用PDMS,DVB/CAR/PDMS,CAR/PDMS三种萃取头,采用固相微萃取技术对锈色粒肩天牛Apriona swainsoni (Hope)幼虫虫粪的挥发物进行了提取,再经气相色谱-质谱联用仪(GC-MS)进行化合物的鉴定.结果表明,虫粪中的挥发性物质主要为萜烯类,其中α-蒎烯的含量最高,柯巴烯的含量次之.三种萃取头在相同的温度和提取时间下,DVB/CAR/PDMS的萃取头的效果最好.     

Three new taxanes with the 10-alkoxy group from the heartwood of Taxus cuspidata

Three novel taxanes with the 10-alkoxy group were isolated from heartwood of Taxus cuspidata. The structures were identified as 2alpha,14beta-diacetoxy-10beta-ethoxytaxa-11,4(20)-dien-5alpha-ol (1), 2alpha,14beta-diacetoxy-10beta-methoxytaxa-11,4(20)-dien-5alpha-ol (2), and 2alpha-acetoxy-10beta-ethoxytaxa-11,4(20)-diene-5alpha,14beta-diol (3) on the basis of spectroscopic analysis. These are the first taxanes with an alkoxy moiety on the skeleton.     

The anatomy, affinity, and phylogenetic significance of Markuelia

The fossil record provides a paucity of data on the development of extinct organisms, particularly for their embryology. The recovery of fossilized embryos heralds new insight into the evolution of development but advances are limited by an almost complete absence of phylogenetic constraint. Markuelia is an exception to this, known from cleavage and pre-hatchling stages as a vermiform and profusely annulated direct-developing bilaterian with terminal circumoral and posterior radial arrays of spines. Phylogenetic analyses have hitherto suggested assignment to stem-Scalidophora (phyla Kinorhyncha, Loricifera, Priapulida). We test this assumption with additional data and through the inclusion of additional taxa. The available evidence supports stem-Scalidophora affinity, leading to the conclusion that scalidophorans, cyclonerualians, and ecdysozoans are primitive direct developers, and the likelihood that scalidophorans are primitively metameric.