Species composition and correlation of understory woody plants in Chinese fir plantation in the lower subtropical area

There are 71 species in the shrub layer of the Cunninghamia lanceolata plantation after natural succession. The species richness and diversity have increased with slight anthropogenic disturbance. The status and function of understory woody species were judged by the analysis of the important value (IV). x ² statistics and r test were used for testing the significance of interspecific association and correlation among 25 main understory woody plants selected from the woody population. The results clearly showed their interspecific relationships and their differences in resource utilization. Species-pairs of positive association were in the majority. Most species were accommodated in the shady habitat. There was a positive correlation between the IV of the species and the interspecific association. The higher the IV of the species, the closer and more significant was the interspecific association. Based on analytical results of interspecific association and correlation, 25 woody plants in the shrub layer could be divided into four ecological species groups: I. Ficus hispida + Antidesma bunius + Mallotus barbatus + Ficus cunia + Saurauia tristyla + Mallotus philippinensis + Maesa japonica + Ficus hirta + Alchornea rugosa + Ficus fulva + Mallotus apelta; II. Cudrania tricuspidata + Schefflera octophylla; III. Cunninghamia lanceolata + Clerodendron cytophyllum + Millettia semicastrata + Randia spinosa + Litsea cubeba + Litsea pungens; IV. Ardisia japonica + Psychotria rubra + Vitex quinata + Cephalanthus occidentalis + Pithecellobium lucidum + Mycetia sinensis. If species group III or II is the advantaged species in the shrub layer, the community would change from a coniferous forest to a sparse evergreen broad-leaved forest. For group IV, the community would be relatively stable. For group I, the coniferous forest would be mixed with coniferous-broad leaved forest. The classification of ecological species groups would provide a theoretical basis on judging its ecological function, adjusting the stand structure of the plantation and directing the suitable natural vegetation type through the close-natural restoration process. __________ Translated from Acta Ecologica Sinica, 2005, 25(9): 2173–2179 [译自: 生态学报, 2005, 25(9): 2173–2179]     

Reduced β2-GPI is associated with increased platelet aggregation and activation in patients with prolonged isolated thrombocytopenia after allo-HSCT

We aimed to measure platelet function and its relationship with β2-GPI in prolonged isolated thrombocytopenia(PT) after allogeneic hematopoietic stem cell transplantation(allo-HSCT). Fifty-six patients with PT and 60 allo-HSCT recipients without PT(non-PT controls) were enrolled. Platelet aggregation and activation, β2-GPI and anti-β2-GPI antibody levels, vWF antigen,and vWF activity were analyzed. The effect of β2-GPI on platelet aggregation was also measured ex vivo. Results showed that ADP-induced platelet aggregation significantly increased(39%±7.5% vs. 23%±8.5%, P=0.032), and the platelet expression of both CD62 p(33.6%±11.6% vs. 8.5%±3.5%, P0.001) and PAC-1(42.4%±7.6% vs. 6.8%±2.2%, P0.001) was significantly higher in patients with PT than in those without PT. Significantly lower β2-GPI levels(164.2±12 μg m L–1 vs. 234.2±16 μg mL–1,P0.001), higher anti-β2-GPI IgG levels(1.78±0.46 U mL–1 vs. 0.94±0.39 U mL–1, P0.001), and increased vWF activity(133.06%±30.50% vs. 102.17%±25.90%, P0.001) were observed in patients with PT than in those without PT. Both ADPinduced platelet aggregation(n=116, r~2=-0.5042, P0.001) and vWF activity(n=116, r~2=-0.2872, P0.001) were negatively correlated with β2-GPI levels. In summary, our data suggested that platelet aggregation and activation were significantly higher in patients with PT than in those without PT, which might be associated with reduced β2-GPI levels. The reduced β2-GPI levels might be due to the existence of anti-β2-GPI IgG.     

Cell-penetrating peptide-mediated transfection of proteins into tissues of Arabidopsis and Chinese cabbage

In Vitro Cellular & Developmental Biology - Plant - Cell-penetrating peptides (CPPs) are a class of short peptides, which have the ability of intracellular delivery. CPPs can also be used as an...     

Techniques for the regeneration and genetic transformation of Arabidopsis pumila: an ephemeral plant suitable for investigating the mechanisms for adaptation to desert environments

Arabidopsis pumila is a type of cruciferous ephemeral plant, which in China mainly grows in the desert environments of northern Xinjiang. A. pumila not only has a short growth duration, but also has high photosynthetic efficiency, seed yield, salt tolerance, and drought resistance. It is an ideal species for the study of environmental adaptations in ephemeral plants. We induced callus tissue formation on the roots and hypocotyls of 8-day-old seedlings, and on the leaves and petioles of 4-week-old seedlings, and obtained multiple adventitious shoots on these tissues grown on Murashige and Skoog induction medium supplemented with 0.5 mg/L 6-Benzylaminopurine and 0.1 mg/L α-Naphthalene acetic acid. Young roots, hypocotyls, leaves, and petioles could all induce calluses, but the induction rate was highest on young roots. In addition, the leaves and petioles of 4-week-old seedlings were used as explants, the Δ1-pyrroline-5-carboxylic acid synthase gene 1 of A. pumila controlled by 35S promoter of cauliflower mosaic virus was used as target gene, and hygromycin B was used as screening antibiotic to explore Agrobacterium tumefaciens GV3101 mediated transformation. The results showed that the callus induction rate of petiole explants was the highest when they were treated with Agrobacterium suspension (OD₆₀₀?=?0.6) for 10 min and thenco-cultured in dark for 2 days. The qRT-PCR results showed that the ApP5CS1.1 gene was overexpressed in the transgenic plants. These protocols provide working research methods for exploring the cellular level adaptative mechanisms of this species to desert environments.

     

Exogenous spermidine improves the sucrose metabolism of lettuce to resist high-temperature stress

Plant Growth Regulation - Lettuce is a popular fresh vegetable, and high-temperature stress will reduce the yield of lettuce. Spermidine is an essential phytohormone in plant stress responses....     

Coloration and phenology manifest nutrient variability in senesced leaves of 46 temperate deciduous woody species

颜色和物候表明46种温带落叶木本植物衰老叶片的养分变异 不同共生植物的叶片养分含量差异显著,反映了不同的叶片养分利用策略。然而,衰老叶片养分的种间变异及其驱动因素尚不清楚。本研究旨在探讨衰老叶片养分的种间变异及其驱动因素。我们在中国东北的帽儿山森林生态系统研究站测定了46种共存温带落叶木本植物新鲜落叶的碳、氮、磷浓度。 采用随机森林模型量化10个生物因素(菌根类型、固氮类型、生长形态、耐阴性、叶片质地、变色程度、变色类型、叶片变色峰期、落叶峰期和落叶末期)的相对重要性。研究结果表明,落叶氮浓度种间变化为4倍,磷浓度变化达9倍。较高的氮和磷平均浓度(15.38和1.24 mg g⁻¹)表明该森林氮和磷限制较弱。功能群仅对特定养分及其比值有显著影响。磷浓度、氮磷比与外生菌根树种的落叶高峰日和落叶结束日呈负相关。颜色鲜艳的叶片(红色＞棕色＞黄色＞黄绿色＞绿色)倾向于比绿色叶片氮和磷浓度更低而碳氮比和碳磷比较高。随机森林模型表明,秋季叶变色和落叶物候贡献了80%的种间变异解释量。这些结果增加了我们对温带森林木本植物营养策略之衰老叶片养分变异性的理解。     

How long should a kiss last between a kinase and its substrate?

In the presence of abscisic acid or environmental stress, activated SnRK2s transiently phosphorylate Raptor1B, a regulatory component of the TOR complex, to inhibit plant growth. To examine such transient interactions between a kinase and its substrate, comprehensive genetic or biochemistry evidence is more conclusive than a single negative co-immunoprecipitation test.