نتایج جستجو برای: xylem

تعداد نتایج: 4505  

Journal: :Tree physiology 2013
Frederick C Meinzer Katherine A McCulloh

For terrestrial plants, maintenance of the integrity of the rootto-leaf water transport pathway is essential for sustaining photosynthetic 9as exchange and growth. The problem of maintaining long-distance water transport is especially challengin9 in trees because path-length resistances and gravity can result in steep gradients of increasing xylem tension from roots to terminal branches, potent...

Journal: :Plant physiology 2003
Loubna Kerkeb Ute Krämer

Exposure of the hyperaccumulator Alyssum lesbiacum to nickel (Ni) is known to result in a dose-dependent increase in xylem sap concentrations of Ni and the chelator free histidine (His). Addition of equimolar concentrations of exogenous L-His to an Ni-amended hydroponic rooting medium enhances Ni flux into the xylem in the nonaccumulator Alyssum montanum, and, as reported here, in Brassica junc...

Journal: :Journal of experimental botany 2006
Wim van Ieperen Annie van Gelder

After the discovery of ion-mediated changes in xylem hydraulic resistance a few years ago, a number of research papers were published that related ion-mediated flow changes in the xylem to various aspects of whole plant functioning and evolutionary diversification of vascular cells. Ion-mediated changes in xylem hydraulic resistance are commonly quantified as the percentile change in hydraulic ...

Journal: :Plant, cell & environment 2016
Uwe G Hacke Joan Laur

This article comments on: Accumulation of sugars in the xylem apoplast observed under water stress conditions is controlled by xylem pH.

Journal: :جنگل و فرآورده های چوب 0
جواد ترکمن استادیار دانشکدۀ منابع طبیعی، دانشگاه گیلان، صومعه‏ سرا، ایران مهرداد قدس خواه دریایی استادیار دانشکدۀ منابع طبیعی، دانشگاه گیلان، صومعه‏سرا، ایران شقایق ذولقدری کارشناس ارشد جنگل‏ شناسی و اکولوژی جنگل، دانشگاه گیلان، صومعه ‏سرا، ایران

dutch elm disease is one of the most destructive and common plant vascular diseases now which isknown as a global problem. the aim of this study was comparison of early- and late-wood vesselsdiameter and ray dimensions. in 4 species: ulmus carpinifolia, zelkova carpinifolia, ulmus glabra andceltis australis from ulmaceae. then, very thin transversal sections were prepared and after differentsta...

Journal: :Tree physiology 2000
H Maherali E H DeLucia

We examined the effects of increased transpiration demand on xylem hydraulic conductivity and vulnerability to cavitation of mature ponderosa pine (Pinus ponderosa Laws.) by comparing trees growing in contrasting climates. Previous studies determined that trees growing in warm and dry sites (desert) had half the leaf/sapwood area ratio (A(L)/A(S)) and more than twice the transpiration rate of t...

2015
Ramesh Katam Kundai Chibanguza Lekan M Latinwo Danyel Smith

Pierce's disease (PD) is a significant threat to grape cultivation and industry. The disease caused by bacterium Xylella fastidiosa clogs xylem vessels resulting in wilting of the plant. PD-tolerant grape genotypes are believed to produce certain novel components in xylem tissue that help them to combat invading pathogens. Research has been aimed at characterizing the uniquely expressed xylem p...

Journal: :Plant physiology 2005
Chengsong Zhao Johanna C Craig H Earl Petzold Allan W Dickerman Eric P Beers

The growth of secondary xylem and phloem depends on the division of cells in the vascular cambium and results in an increase in the diameter of the root and stem. Very little is known about the genetic mechanisms that control cambial activity and the differentiation of secondary xylem and phloem cell types. To begin to identify new genes required for vascular cell differentiation and function, ...

Journal: :Plant physiology 1980
J S Pate C A Atkins S T White R M Rainbird K C Woo

Xylem sap composition was examined in nodulated and nonnodulated cowpea (Vigna unguiculata [L.] Walp.) plants receiving a range of levels of NO(3) and in eight other ureide-forming legumes utilizing NO(3) or N(2) as sole source of nitrogen. A (15)N dilution technique determined the proportions of plant nitrogen derived from N(2) in the nodulated cowpeas fed NO(3). Xylem sap composition of NO(3)...

Journal: :Journal of experimental botany 2012
Benjamin Bollhöner Jakob Prestele Hannele Tuominen

Evolutionary, as well as genetic, evidence suggests that vascular development evolved originally as a cell death programme that allowed enhanced movement of water in the extinct protracheophytes, and that secondary wall formation in the water-conducting cells evolved afterwards, providing mechanical support for effective long-distance transport of water. The extant vascular plants possess a com...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید