Location: Crops Pathology and Genetics ResearchTitle: Grapevine species from varied native habitats exhibit differences in embolism formation/repair associated with leaf gas exchange and root pressure
|Knipfer, Thorsten - University Of California|
|Brodersen, Craig - Yale University|
|Walker, Andrew - University Of California|
Submitted to: Plant Cell and Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/15/2015
Publication Date: 1/31/2015
Publication URL: http://onlinelibrary.wiley.com/doi/10.1111/pce.12497/full
Citation: Knipfer, T., Eustis, A.J., Brodersen, C., Walker, A., Mcelrone, A.J. 2015. Grapevine species from varied native habitats exhibit differences in embolism formation/repair associated with leaf gas exchange and root pressure. Plant Cell and Environment. 38:1503-1513.
Interpretive Summary: Drought stress can cause water transport tissue (xylem) in plants to become blocked with air bubbles (embolism). Grapevines are known to repair embolism once they form in the water conducting tubes, but it is not known whether this capability differs among grapevine species. We used micro-computed tomography (a type of CT scan) to look inside grapevine xylem subjected to drought and recovery after rewatering. We found that the species differed in the amount of embolism formed in their xylem under drought and differed in their ability to repair embolism once it formed. This information can be used to select for improved drought resistance in grapevine rootstocks.
Technical Abstract: Drought induces xylem embolism formation, but grapevines can refill blocked conduits to restore transport capacity. It is unknown whether vulnerability to embolism formation and ability to repair differ among grapevine species. We analyzed in vivo embolism formation and repair using x-ray microtomography in three wild grapevine species from varied native habitats (Vitis riparia, V. arizonica, V. champinii), and related responses to measurements of leaf gas exchange and root pressure. Vulnerability to embolism formation was greatest in V. riparia, intermediate in V. arizonica, and lowest in V. champinii. After re-watering, embolism repair was rapid and pronounced in V. riparia and V. arizonica, but limited or negligible in V. champinii even after numerous days. Similarly, root pressure measured after re-watering was positively correlated with drought stress severity for V. riparia and V. arizonica (species exhibiting embolism repair) but not for V. champinii. Drought-induced reductions in transpiration were greatest for V. riparia and least in V. champinii. Recovery of transpiration after re-watering was delayed for all species, but was greatest for V. champinii and most rapid in V. arizonica. These species exhibit varied responses to drought stress that involve maintenance/recovery of xylem transport capacity coordinated with root pressure and gas exchange responses.