Comparative Analysis of Endogenous Hormones and Metabolite Profiles in Early-Spring Flowering Plants and Unflowered Plants Revealing the Strategy of Blossom

Journal of Plant Growth Regulation - Early-spring plants are a special type of plant that complete their life cycle promptly in cold, early spring. Very little effort has been made into researching...     

Prenatal diagnosis of Pallister-Killian syndrome and literature review

Pallister-Killian syndrome (PKS) is a rare sporadic genetic disorder usually caused by mosaicism of an extra isochromosome of 12p (i(12p)). This retrospective study analysed the prenatal ultrasound manifestations and molecular and cytogenetic results of five PKS foetuses. Samples of amniotic fluid and/or cord blood, skin biopsy and placenta were collected. Conventional karyotyping and single nucleotide polymorphism array (SNP array) were performed on all the amniotic fluid or cord blood samples. Copy number variants sequencing (CNV-seq) and fluorescence in situ hybridization (FISH) were also used for the validation for one foetus. All the five foetuses were from pregnancies with advanced parental age. Two foetuses involved structural abnormalities and one foetus had only soft markers, all of which included increased nuchal translucency. The rest two foetuses had normal ultrasounds in the second trimester, which has rarely been reported before. The karyotype revealed typical i(12p) in four cases and a small supernumerary marker chromosome consisting of 12p and 20p in the remaining one case. The proportion of cells with i(12p) ranged from 0 to 100% in cultural cells, while SNP array results suggested 2−4 copies of 12p. For one foetus, metaphase FISH showed normal results, but the interphase FISH suggested cell lines with two, three and four copies of 12p in the amniotic fluid. Advanced parental age may be an important risk factor for PKS, and there were no typical ultrasound manifestations related to PKS. A combination of karyotype analysis and molecular diagnosis is an effective method for the diagnosis of PKS.     

用2DNMR鉴定倍半萜多元酯的结构

利用2DNMR结合其他波谱方法从苦皮藤种子油中鉴定了2个新倍半萜多元酯,它们分别是1α-苯甲酰氧-8β-烟酰氧-9α、11β-2乙酰氧-β-二氢沉香呋喃,1β-苯甲酰氧-2α、8β、9α、11β-4乙酰氧-β-二氢沉香呋喃,命名为苦皮藤酯2和3。     

Physiological aspects of Taxus brevifolia seeds in relation to seed storage characteristics

Water relations, desiccation tolerance and longevity of Taxus brevifolia (Nutt.) seeds were studied to determine the optimal stage of development and storage conditions for seeds of this species. Seeds equilibrated to a range of relative humidities (RHs) had unusually low water contents which can be accounted for by the high lipid content of gametophyte tissues (71% of the dry mass). Water relations of embryonic tissue were more typical of those reported for other seed species. The water content below which freezing transitions were not observable in the embryo was ca 0.24 g H₂O (g dry weight)⁻¹ (g g⁻¹) for all maturity classes studied. Embryos did not achieve significant levels of desiccation tolerance (survival to water contents less than 0.5 g g⁻¹) until the latter stages of development when dry matter was maximal. Mature embryos could be dried to 0.025 g g⁻¹ (seed water content of 0.010 g g⁻¹) with no loss of viability. Thus, at the latter stages of development, embryo water content could be optimized to avoid both desiccation and freezing damage. Survival of mature seeds declined over a 2-year period when seeds were stored at temperatures between 5 and 35°C and RHs between 14 and 75%, corresponding to seed water contents between 0.015 and 0.07 g g⁻¹. The deterioration rate was slowest for seeds stored at the lowest RH and temperature. Our data indicate that seeds of Taxus brevifolia show orthodox rather than recalcitrant storage characteristics, but that the optimum water content for storage was extremely low. The results suggest that even if stored at optimal water contents and low temperatures, T. brevifolia seeds will be relatively short lived. The high quantity of lipids or reducing sugars may be contributing factors in the poor storage characteristics.     

武汉东湖水生植被及其恢复途径探讨

１９９２～１９９３年对武汉东湖三个主要湖区（郭郑湖、汤林湖和牛巢湖）水生植被的调查表明,该湖区共有水生植物３２种,优势种为大茨藻、狐尾藻、苦草和菱。金鱼藻呈不断扩大的趋势。植被类型可分为１１个群丛,植被面积约为０．６５ｋｍ￣２,总生物量为１２３６．３９ｔ（湿重）,植被带状分布仅见于汤林湖北部和其他部分湖汊。汤林湖和牛巢湖水生植被正处于自然恢复演替阶段。     

Factors affecting gene delivery by particle bombardment ofDendrobium orchids

Summary Five parameters were examined for their effect on transformation ofDendrobium tissues by microprojectile bombardment. The superpromoter in pBI426 produced at least 1.5 times as many transient transformants as the single cauliflower mosaic virus 35S promoter in pBI121 (37 to 69% vs. 0 to 44%) with dark and frequent GUS (β-glucuronidase) staining. Tissue, genotype, and type of microparticle significantly affected transient GUS activity. Higher expression was seen in protocormlike bodies and in hybrid UH44 compared to etiolated shoots and protocorms and to hybrids M61 and K1329-39. Microparticles of 1.6-μm Bio-Rad gold were more effective than 1.0-μm ASI gold. Transient GUS activity did not differ among protocormlike bodies bombarded using helium propellant pressures of 650, 900, or 1100 psi. Transgenic plants were recovered fromDendrobium UH800 protocormlike bodies bombarded with pBI426-coated, 1.1-μm tungsten particles using an early-model gunpowder-driven apparatus with an estimated stable transformation rate of 11.7%. One transgenic plant ofDendrobium UH44 was recovered from etiolated shoot explants bombarded with pBI121-coated, 1.1-μm tungsten particles using the Dupont PDS-1000 with a stable transformation rate of 0.17%. Positive selection results showed 100 to 200 mg·liter⁻¹ kanamycin to be appropriate for regeneration of transgenic plants from protocormlike bodies, protocorms, and etiolated shoot explants over a 3- to 9.5-mo. period.     

Logistic曲线参数的一个最佳估计方法

本文提出用O．628优选法和SAS/STAT软件NLIN模块中的DUD法,对Logistic曲线中的参数k,a和b可得到最佳估计。     

Upgrading the genome of an elite japonica rice variety Kongyu 131 for lodging resistance improvement

Developing a new rice variety requires tremendous efforts and years of input. To improve the defect traits of the excellent varieties becomes more cost and time efficient than breeding a completely new variety. Kongyu 131 is a high-performing japonica variety with early maturity, high yield, wide adaptability and cold resistance, but the poor-lodging resistance hinders the industrial production of Kongyu 131 in the Northeastern China. In this study, we attempted to improve the lodging resistance of Kongyu 131 from perspectives of both gene and trait. On the one hand, by QTL analysis and fine mapping we discovered the candidate gene loci. The following CRISPR/Cas9 and transgenic complementation study confirmed that Sd1 dominated the lodging resistance and favourable allele was mined for precise introduction and improvement. On the other hand, the Sd1 allelic variant was identified in Kongyu 131 by sequence alignment, then introduced another excellent allelic variation by backcrossing. Then, the two new resulting Kongyu 131 went through the field evaluation under different environments, planting densities and nitrogen fertilizer conditions. The results showed that the plant height of upgraded Kongyu 131 was 17%–26% lower than Kongyu 131 without penalty in yield. This study demonstrated a precise and targeted way to update the rice genome and upgrade the elite rice varieties by improving only a few gene defects from the perspective of breeding.