Abstract Detail

Xylem apoplast-symplast interactions

Jacobsen, Anna [1].

Xylem vessel development: The prevalence of differentiating, living, and hydraulically functional vessel elements in grapevine.

Vessel elements may exhibit delayed maturation in some species, particularly those exhibiting rapid shoot elongation. This pattern has been described in both tree and liana species, including poplar and grapevine. The maintenance of a large proportion of living vessels may allow plants to maintain transport homeostasis by controlling the activation of vessels following the loss of functionality in some vessels due to cavitation. Additionally, well documented seasonal changes in xylem conductivity and cavitation resistance may be related to the activation of new cohorts of vessels from the pool of living vessels within the stem throughout the growing season. We examined several varieties of grapevine and used a staining protocol to determine the prevalence and location of living vessels within the xylem of one year old stems ranging from 5-12 mm in diameter. We found a significant proportion of non-hydraulically active vessels (approximately 33%) within the xylem of several varieties of grapevine, including Chardonnay and Glenora. Living vessel elements appeared mature in the absence of staining, but staining revealed that they contained living protoplasm. Interestingly, these vessels could be quite far from the cambium and were surrounded by a fully formed matrix of fibers. A smaller proportion of these vessels, those closest to the cambium, were still developing and had not yet fully formed their secondary cell wall. The vessel network of plants is dynamic and an important characteristic is the ability to recruit new vessels. The presence of non-hydraulically active, living vessels within the xylem has implications for understanding the development of hydraulic connections within the xylem, for interpretation of measures of plant hydraulics, and for understanding the connectivity of the xylem apoplast and symplast.

Broader Impacts:

1 - California State University Bakersfield, 9001 Stockdale Hwy, 61 SCI, Bakersfield, CA, 93311, USA, 310-740-7659

Keywords:
xylem
grapevine
vessels
Development
hydraulic conductivity
cavitation
Embolism
tyloses
water relations
water potential.

Presentation Type: Symposium or Colloquium Presentation
Session: C3
Location: Belle-Chasse/Riverside Hilton
Date: Monday, July 29th, 2013
Time: 11:15 AM
Number: C3013
Abstract ID:687
Candidate for Awards:None