Water-use efficiency in rice (Oryza sativa L.) in relation to resistance to salinity

Abstract The effects of sodium chloride on water-use efficiency of a number of varieties of rice have been investigated. Sensitivity to salinity in rice arises in large part from excessive rates of sodium ion transport to the shoot consequent upon high rates of transpirational water loss. Varietal differences in water-use efficiency were found: these were greater when measured for whole shoots over a period of one week, than when made as instantaneous measurements on individual leaves. Salinity had rather little effect on water use efficiency but overall resistance of seedlings to salt was, in general, greater the greater the water-use efficiency. The reasons for the differences between varieties are discussed in terms of differences in growth pattern: among the seven varieties investigated, water-use efficiency and salt-resistance were lower in dwarfed as opposed to non-dwarfed varieties.     

STIM1-Ca(2+) signaling is required for the hypertrophic growth of skeletal muscle in mice

Immediately after birth, skeletal muscle must undergo an enormous period of growth and differentiation that is coordinated by several intertwined growth signaling pathways. How these pathways are integrated remains unclear but is likely to involve skeletal muscle contractile activity and calcium (Ca(2+)) signaling. Here, we show that Ca(2+) signaling governed by stromal interaction molecule 1 (STIM1) plays a central role in the integration of signaling and, therefore, muscle growth and differentiation. Conditional deletion of STIM1 from the skeletal muscle of mice (mSTIM1(-/-) mice) leads to profound growth delay, reduced myonuclear proliferation, and perinatal lethality. We show that muscle fibers of neonatal mSTIM1(-/-) mice cannot support the activity-dependent Ca(2+) transients evoked by tonic neurostimulation, even though excitation contraction coupling (ECC) remains unperturbed. In addition, disruption of tonic Ca(2+) signaling in muscle fibers attenuates downstream muscle growth signaling, such as that of calcineurin, mitogen-activated protein (MAP) kinases, extracellular signal-regulated kinase 1 and 2 (ERK1/2), and AKT. Based on our findings, we propose a model wherein STIM1-mediated store-operated calcium entry (SOCE) governs the Ca(2+) signaling required for cellular processes that are necessary for neonatal muscle growth and differentiation.     

绿色木霉菌LTR-2孢子提取物的抑菌活性及化学成分分析

通过研究绿色木霉菌LTR-2分生孢子提取物的抑菌活性及化学成分,为进一步提取纯化新型抗生素提供依据。采用固体麸皮培养基培养绿色木霉菌LTR-2,以二氯甲烷浸提法提取分生孢子中的抗菌物质,采用菌丝生长法测定提取物的抑菌活性,并用气相色谱-质谱联用仪进行分析,峰面积归一法计算有关成分的相对含量。绿色木霉菌LTR-2分生孢子的提取物抑菌谱广,对供试11种植物病原真菌均有不同程度的抑制作用;抑制效果好,对禾谷丝核菌的抑制率为89.3%。从提取物中分离鉴定出60多种化学成分,其中烷烃类成分数量最多,为43种,其他成分有酮类、有机酸类、醇类、烯类等,主要成分是麦角固醇,含量为41.90%。结论:绿色木霉菌LTR-2分生孢子提取物具有抑菌作用。通过化学成分分析,提取物中含有化合物5,6-二氢-6-戊基-2H-吡喃-2-酮,含量为2.35%,结合文献报道,推测5,6-二氢-6-戊基-2H-吡喃-2-酮是提取物中起抑菌作用的物质。     

在鱼腥藻7120中建立反义glnA系统

应用反义技术对鱼腥藻7120切的内源glnA基因的表达进行调控,首次获得了人工反义系统的蓝藻品系。先从编码谷酰胺合成酶（GS）的基因glnA中取得部分结构基因片段,与表达质粒载体pRL-439及穿梭质粒载体pDC－8相连接。通过酶切鉴定筛选出反向克隆的穿梭表达质粒pDC－AM,然后应用三亲接合转移法把它转入鱼腥藻对7120.通过新霉素筛选,酶谱鉴定,斑点杂交,质粒的交叉转化以及内源glnA基因表达的GS活性分析,GS相关的胞外泌氨分析及所获藻株的形态学变化,证明已在鱼腥藻7120中建立了人工反义glnA基因的品系。     

Population-specific quantitative trait loci mapping for functional stay-green trait in rice (Oryza sativa L.)

The functional stay-green trait gives leaves a longer duration of greenness and photosynthetic capacity during the grain-filling period. We developed two independent recombinant inbred line populations from the intra- and intersubspecific crosses of Oryza sativa L. subsp. japonica 'Suweon490' (japonica) × O. sativa subsp. japonica 'SNU-SG1' (japonica) and O. sativa subsp. indica 'Andabyeo' (indica) × O. sativa subsp. japonica 'SNU-SG1' (japonica), respectively. The common parental line 'SNU-SG1' was the functional source for the stay-green trait. Quantitative trait locus (QTL) mapping based on simple sequence repeat markers identified a total of six QTLs associated with two stay-green traits across two populations. The two traits were cumulative chlorophyll content (SPAD value) of flag leaf (CSFL) and total cumulative SPAD value of the four upper leaves (TCS). Four QTLs, tcs4, csfl6, csfl9 (or tcs9), and csfl12, located on chromosomes 4, 6, 9, and 12, respectively, were detected simultaneously in both populations. The remaining two QTLs, csfl2 (or tcs2) and tcs5, on chromosomes 2 and 5, respectively, were found to be population specific. Moreover, the functional stay-green trait of 'SNU-SG1' positively correlated with grain yield performance. Two yield QTLs, yld6 and yld9, on chromosomes 6 and 9 found in both populations were positioned at the same locations with the csfl6 and tcs9 QTLs for stay-green traits. Thus, the identified chromosomal regions can be promising targets of marker-assisted introgression of the functional stay-green trait into breeding materials for improvement of rice yield.     

木霉现有种类名录

木霉因其在酶、抗生素及生防等方面有着重要的经济生产价值而得到世界广泛的研究和关注。截止目前,已报道木霉种类达到212种,准确对其进行分类和鉴定对于木霉的研究和利用有着重要的意义。本文整理了目前已报道的木霉种类名录及用于木霉系统发育种类鉴定的分子技术和工具,这些技术和工具为木霉研究者对木霉进行准确种类鉴定提供技术指导和帮助。     

洞庭湖湿地木霉多样性及生防活性

【目的】了解湖南省洞庭湖湿地木霉种类及分布,丰富我国的木霉种质资源,为功能菌株筛选应用奠定基础。【方法】利用ITS序列比对分析结合形态学特征对分离到的木霉菌株进行种类鉴定,构建系统发育进化树分析其亲缘关系。通过菌丝生长速率法测定菌株的平板抑菌能力,根据水解带大小检测菌株的水解酶活性,利用灰色关联度分析筛选综合生防效果较好的木霉菌株。【结果】从52个土样和18个水样中分离得到114株木霉菌株,经鉴定分属16个木霉种类:哈茨木霉、绿木霉、刺孢木霉、土星孢木霉、钩状木霉、拟康宁木霉、短密木霉、深绿木霉、猥木霉、毛细木霉(中国新记录种)、长枝木霉、卵孢木霉、侧耳木霉、加纳木霉、厚木霉及一个疑似新种;哈茨木霉为洞庭湖湿地中的优势种,占总菌株数量的19.30%;16种木霉在系统发育树中归于7个进化支:Harzianum Clade、Virens Clade、Longibrachiatum Clade、Lutea Clade、Viride Clade、Hamatum Clade、Unknown Clade。灰色关联度分析表明,菌株TW21990、QT22040和QT22094的灰色关联度较高,分别为0.849 5、0.798 6和0.732 6,综合生防性状较好。【结论】洞庭湖湿地木霉具有种类多样性和分布多样性,发现了一个中国新记录种毛细木霉和一个疑似新种,哈茨木霉TW21990、长枝木霉QT22040和卵孢木霉QT22094是潜在的优良生防菌株。     

Salt Tolerance in the Halophyte Suaeda maritima L. Dum.: Intracellular Compartmentation of Ions

The time-course of exchange of sodium and potassium ions fromroot and leaf material of the halophyte Suaeda maritima hasbeen followed and the data analysed according to the phenomenologyof efflux, or compartmental, analysis. Sodium ions were exchangedmuch more slowly (c. 4 times) from the vacuoles of leaf cellsof plants grown in sodium chloride than were potassium ionsfrom the vacuoles of leaf cells of plants grown either in similarconcentrations of potassium chloride or in low concentrationsof potassium. In plants grown in sodium chloride, sodium ionswere exchanged 9 times more slowly from the vacuoles of leafcells than from the vacuoles of root cells. The concentration of sodium ions in the cytoplasm of leaf cellsof plants growing in 340 mol m^–3 sodium chloride was estimatedto be 165 mol m^–3 when the average concentration in theleaf tissue was about 600 mol m^–3. As measured by movement from mature to developing leaves inintact plants; there was less in vivo retranslocation of ²²Naand ³⁶CI in plants growing in sodium chloride than there wasof ⁸⁶Rb in plants growing either in potassium chloride or innon-saline conditions. The results are discussed in terms of the concept and energeticsof compartmentation of ions in the cells of halophytes.     

The biology and systematics of Geranium, sections Anemonifolia Knuth and Ruberta Dum.

The external morphology of the six species is considered in detail, special attention being given to the branching System, flower form and the type of seed dispersal, which has often been misunderstood and has parallels among basidiomycete Fungi. In addition petiole anatomy is described, all species being different, and unpublished chromosome counts by other workers are reported (including 2n = 128 for G. canariense , a number erroneously reported earlier for G. palmatum). Crossing experiments (partly carried out by Mr W. Jackson) are described; the only successful new interspecific cross was G. maderense x G. palmatum. It is concluded that the six species, some of which are large pachycaul herbs endemic to Madeira or the Canary Islands, form an advanced group, and their affinities are discussed. A survey of other species with the same seed-discharge mechanism, and of annual or biennial species, suggests that among the latter decrease in chromosome number has taken place along several different lines, and it is suggested that thèse lowered numbers have been combined by amphidiploidy to create new basic numbers in the genus. A formal taxonomic treatment of sections Anemonifolia and Ruberta includes observations on infraspecific variation. An appendix reports the chromosome number of G. cataractarum as 2n = 36.