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1.
Ming Pei You Brandon Lancaster Krishnapillai Sivasithamparam Martin John Barbetti 《Plant and Soil》2008,302(1-2):203-211
In Australia, in the past, pasture legumes were rotated mainly with cereals, but increasingly these rotations now involve
pasture legumes with a wider range of crops, including legumes. This increasing frequency of the leguminous host in the rotation
system may be associated with increased root rots in legumes in the current pasture-crop rotations. The primary aim of this
study was to see whether the pathogenicity on pasture legumes of strains of Rhizoctonia solani sourced from lupins and cereals (common crops in rotation with pastures) is associated with increased incidence of root rots
in pasture legumes in the disease conducive sandy soils of the Mediterranean regions of southern Australia. The second aim
was to determine sources of resistance among newly introduced pasture legumes to R. solani strains originating from rotational crops as this would reduce the impact of disease in the pasture phase. Fifteen pasture
legume genotypes were assessed for their resistance/susceptibility to five different zymogram groups (ZG) of the root rot
pathogen R. solani under glasshouse conditions. Of the R. solani groups tested, ZG1–5 and ZG1–4 (both known to be pathogenic on cereals and legumes) overall, caused the most severe root
disease across the genotypes tested, significantly more than ZG6 (known to be pathogenic on legumes), in turn significantly
>ZG4 (known to be pathogenic on legumes) which in turn was >ZG11 (known to be pathogenic on legumes including tropical species).
Overall, Ornithopus sativus Brot. cvs Cadiz and Margurita, Trifolium michelianum Savi. cvs Paradana and Frontier and T. purpureum Loisel. cv. Electro showed a significant level of resistance to root rot caused by R. solani ZG11 (root disease scores ≤1.2 on a 1–3 scale where 3 = maximum disease severity) while O. sativus cvs Cadiz and Erica showed a significant level of resistance to root rot caused by R. solani ZG4 (scores ≤1.2). O. compressus L. cvs Charano and Frontier, O. sativus cv. Erica, and T. purpureum cv. Electro showed some useful resistance to root rot caused by R. solani ZG6 (scores ≤1.8). This is the first time that cvs Cadiz, Electro, Frontier, Margurita and Paradana have been recognised
for their levels of resistance to root rot caused by R. solani ZG11; and similarly for cvs Cadiz and Erica against ZG4; and for cvs Charano, Erica, and Electro against ZG6. These genotypes
with resistance may also serve as useful sources of resistance in pasture legume breeding programs and also could potentially
be exploited directly into areas where other rotation crops are affected by these R. solani strains. None of the tested genotypes showed useful resistance to R. solani ZG1–4 (scores ≥2.0) or ZG1–5 (scores ≥2.5). This study demonstrates the relative potential of the various R. solani ZG strains, and particularly ZG1–4, ZG1–5, ZG4 and ZG6 to attack legume pastures and pose a significant threat to non-pasture
crop species susceptible to these strains grown in rotation with these pasture legumes. Significantly, the cross-pathogenicity
of these strains could result in the continuous build-up of inoculum of these strains that may seriously affect the productivity
eventually of legumes in all rotations. In particular, when choosing pasture legumes as rotation crops, caution needs to be
exercised so that the cultivars deployed are those with the best resistance to the R. solani ZGs most likely to be prevalent at the location. 相似文献
2.
Household‐level correlates of children's physical activity levels in and across 12 countries 下载免费PDF全文
Deirdre M. Harrington Fiona Gillison Stephanie T. Broyles Jean‐Philippe Chaput Mikael Fogelholm Gang Hu Rebecca Kuriyan Anura Kurpad Allana G. LeBlanc Carol Maher Jose Maia Victor Matsudo Timothy Olds Vincent Onywera Olga L. Sarmiento Martyn Standage Mark S. Tremblay Catrine Tudor‐Locke Pei Zhao Peter T. Katzmarzyk for the ISCOLE Research Group 《Obesity (Silver Spring, Md.)》2016,24(10):2150-2157
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4.
Lck-dependent tyrosyl phosphorylation of the phosphotyrosine phosphatase SH-PTP1 in murine T cells. 总被引:15,自引:2,他引:13 下载免费PDF全文
U Lorenz K S Ravichandran D Pei C T Walsh S J Burakoff B G Neel 《Molecular and cellular biology》1994,14(3):1824-1834
The phosphorylation and dephosphorylation of proteins on tyrosyl residues are key regulatory mechanisms in T-cell signal transduction and are controlled by the opposing activities of protein tyrosine kinases and phosphotyrosyl phosphatases (PTPs). In T cells, several nontransmembrane protein tyrosine kinases are associated with receptors; for example, Lck is bound to the coreceptors CD4 and CD8 and becomes activated upon their stimulation. In comparison, little is known about the role of nontransmembrane PTPs in early T-cell signaling. SH-PTP1 (PTP1C, HCP, SHP) is a nontransmembrane PTP expressed primarily in hematopoietic cells, including T cells. We have found that SH-PTP1 is basally phosphorylated on serine in resting T cells. Upon stimulation of CD4 or CD8 either in a T-cell hybridoma cell line or in primary thymocytes, SH-PTP1 becomes tyrosyl phosphorylated. Moreover, SH-PTP1 is constitutively phosphorylated on tyrosine in the Lck-overexpressing lymphoma cell line LSTRA. SH-PTP1 is also a good substrate for recombinant Lck in vitro. Comparisons of the tryptic phosphopeptide maps of wild-type SH-PTP1 and deletion and point mutations establish that the two sites (Y-536 and Y-564) which are directly phosphorylated by Lck in vitro are also phosphorylated in vivo in LSTRA cells. One of these sites (Y-564) is phosphorylated in T cells in response to Lck activation. We conclude that SH-PTP1 undergoes Lck-dependent tyrosyl phosphorylation in T cells and likely plays a role in early T-cell signaling. 相似文献
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6.
质体醌重组的D1/D2/Cytb559复合物的荧光衰减动力学和光破坏作用 总被引:3,自引:0,他引:3
光系统Ⅱ反应中心D1/D2/Cytb559 在分离纯化过程中失去了电子受体QA 和QB,人工合成的质体醌可以与D1/D2/Cytb559 复合物发生重组。癸基质体醌(DPQ)与D1/D2/Cytb599 复合物的重组导致该复合物的荧光强度下降及发射光谱蓝移,同时两个与光化学活性相关的长寿命(24 ns和73 ns)荧光衰减组分占整个荧光的百分数下降,这些结果表明DPQ作为Pheo- 的电子受体,限制了P680+ ·Pheo- 的电荷重组。DPQ 的加入对D1/D2/Cytb559复合物中Chla 分子的光破坏敏感性影响不大,但β-胡萝卜素在加入DPQ 之后可以被光照破坏,这个过程可能与β-胡萝卜素的生理功能相关。 相似文献
7.
几种濒危植物及其近缘类群总DNA的提取与鉴定 总被引:122,自引:0,他引:122
用低pH 介质,高盐沉淀蛋白质方法成功地从银杉(Cathaya argyrophylla Chun etKuang)、矮牡丹(Paeonia suffruticosa var. spontanea)、南川升麻(Cim icifuga nanchuanensisHsiao)、裂叶沙参(Adenophora lobophylla)的同属种泡沙参(A. potaninii)等植物中提取和部分纯化了细胞总DNA,并对其产率、质量和纯度作了鉴定。此方法的关键是用了一个低pH提取介质,它能有效防止组织破碎及沉淀大量材料时的电离化作用及酚化合物的进一步氧化。所得DNA 不需经氯化铯梯度离心或柱层析,直接可用于限制性片断长度多态性(RFLP)及随机扩增的DNA多态性(RAPD)等分子水平的遗传标记。为检测濒危植物的遗传多样性提供了一套迅速、简便和可靠的技术方案 相似文献
8.
玉米种子萌发成苗不同阶段需水阈值的研究 总被引:7,自引:0,他引:7
用渗透势不同的聚乙二醇(PEG)6000模拟外界环境水分条件,对玉米不同品种的种子在萌动、萌发及成苗三个阶段需水的量化研究表明,种苗的抗旱性随吸水进程的推进而减弱;种子在萌动、萌发及胚芽伸长至一定长度的时间(t)与外界环境水势(w)之间存在着1/t=a+bw的关系,据此推算出不同品种在不同成苗阶段的需水阈值,发现不同品种在同一成苗过程中对环境水分条件的反应不同,它们的抗旱性也不同。 相似文献
9.
利用单克隆抗体免疫磁珠吸附方法分离脐血CD34+细胞,并观察了IL3/GMCSF融合蛋白(PIXY321)对脐血CD34+细胞的刺激作用。PIXY321对脐血CD34+细胞扩增作用大于IL3和GMCSF单独及联合应用。在液体培养条件下,每毫升20ngPIXY321可有效地扩增脐血造血祖细胞,适宜扩增时间为5-8天,扩增后造血祖细胞的数量可达扩增前的8-10倍,从而初步建立了一种简单可行的脐血造血细胞扩增方法。 相似文献
10.
宁夏分布有大面积的流动沙地和盐碱地,因此,引进适生的植物对治沙造林、改善生态环境有重大意义。本文报道沙拐枣属(Calligonum L.)和柽柳属(Tamarix L.)的引选及抗逆性造林技术方面的结果。 相似文献