Prof. Amnon Schwartz

 

Research Interests:

Plant water relations, Calcium transport and distribution in the whole plant, Photosynthesis and stomatal conductance, Irrigation scheduling based on physiological parameters.

Current Projects:

  • Internal and external factors that control oscillation of stomata conductance in banana leaves.
  • Simplistic versus Apoplectic pathway of water and solute transport within leaves.
  • Regulated deficit irrigation (RDI) of grape wins: effects on yield and wine quality.
  • Photosynthetic and photoprotective adaptation of date palm leaves to water quality and extreme temperatures.
  • Prevention of degeneration and die out of fruit tree orchards irrigated with recycled treated wastewater.

Research Projects

Applied research project: Irrigation of orchards using the regulated deficit irrigation (RDI) method

Efficient irrigation requires precise information on crop water consumption to ensure the correct scheduling and quantity of water and fertilizer to be applied. In recent years, research done by my group has focused on developing irrigation models based on physiological parameters, to serve as guidelines for the planning of efficient orchard irrigation programs. Our research is guided by the hypothesis that by skilled planning of irrigation, growers can increase fruit yield and fruit quality while maintaining a high level of water-use efficiency.

Basic research project: Water and solute transport in leaves

In banana leaves, the transport of water and solutes from the xylem of the veins to the mesophyll and epidermis is mediated by vascular bundle sheath tissue, which is analogous to the endodermis of the root. The results of a study of the mode of ion distribution in the lamina of banana leaves led to the conclusion that the symplast, not the apoplast is the main pathway for the transport of water and solutes from the leaf xylem toward the mesophyll and epidermis.

We have proposed a model that explains the accumulation of Na+ and boron in the laminar margins of banana leaves, suggesting a role for the bundle sheath tissue of the laminar veins in the "active filtration" of the xylem sap, in order to prevent toxic concentrations of ions from reaching the photosynthetic tissue. Boron, manganase and other ions that are toxic to the photosynthetic tissue at high concentrations are effectively confined to the vascular system, to be disposed of in the tissue of the lamina margin or to be released from the lamina by guttation during the night.

 

List of Publications

Wigoda N., Ben-Nissan G., Granot D., Schwartz A. and Weiss D. (2006) 
The gibberellin-induced, cysteine-rich protein GIP2 from Petunia hybrida exhibits in-planta antioxidant activity.
Plant J. 48: 796-805.

Maseyk KS., Lin T., Rotenberg E., Grünzweig JM., Schwartz A., Yakir D (2008) 
Physiology-phenology interactions in a productive semi-arid pine forest 
New Phytologist 178: 603-616

Netzer, Y., Yao C., Shenker M., Bravdo B., Schwartz A. (2008). 
Water use and the development of seasonal crop coefficients for Superior Seedless grapevines trained to an open-gable trellis system
Irrig. Sci. 27:109-120

Arel R., Dag A., Ben-Gal A., Schwartz A., and Yermiyahu, U. (2008). 
Flowering and fruit set of olive trees in response to nitrogen, phosphorus and potassium
J. Amer. Soc. Hort. Sci.(accepted).

Shapira O., Khadka S., Israeli Y., Shani U., & A. Schwartz (2009) 
Functional anatomy controls ion distribution in banana leaves: significance of Na+ seclusion at the leaf margins
Plant Cell & Environment 32: 476-485

Villordon AQ., La Bonte DR., Firon N., Kfir Y., Pressman E., Schwartz A. (2009) 
Characterization of Adventitious Root Development in Sweet potato
HortScience 44:651-655

Westhoff M., Reuss R., Zimmermann D., Netzer Y., Gessner A., Geßner P., Zimmermann G., Wegner LH.,.; Bamberg E., Schwartz A., Zimmermann U. (2009) 
A non-invasive probe for online-monitoring of turgor pressure changes under field conditions. Plant Biology, 11: 701-712

Zimmermann U., Rüger S., Shapira O., Westhoff M., Wegner L. H., Reuss R.,Gessner P., Zimmermann G., Israeli Y., Zhou A., Schwartz A., Bamberg E., Zimmermann D. (2009) 
Effects of environmental parameters and irrigation on the turgor pressure of banana plants measured using the non-invasive, online monitoring leaf patch clamp pressure probe
Plant Biology. 12: 424-436.

Rüger S., Netzer Y., Westhoff, L. H., Zimmermann D., Reuss R., Ovadya S., Gessner P., Zimmermann G., Schwartz A. , and U. Zimmermann. (2010) 
Remote monitoring of leaf turgor pressure of grapevines subjected to different irrigation treatments using the leaf patch clamp probe
Australian Journal of Grape and Wine Research. 16(3) 405-412. DOI: 10.1111/j.1755-0238.2010.00101.x

Sade N., Gebretsadik M., Seligmann R., Schwartz A., Wallach R. and Moshelion M. (2010). 
The Role of Tobacco Aquaporin1 in Improving Water Use Efficiency, Hydraulic Conductivity, and Yield Production Under Salt Stress
Plant Physiology 152:245-254.

Arel R., Dag A., Ben-Gal A., Schwartz A., Cohen S., (2011). 
Use of a greenhouse as an open chamber for canopy gas exchange measurements: Methodology and validation
Agricultural and Forest Meteorology 151: 1346-1355.

Boneh U. Biton I. Schwartz A. and G. Ben-Ari. (2012). 
Characterization of the ABA signal transduction in Vitis vinifera
Plant Science 187 : 89-96

Sperling O., Shapira O., Cohen S., Tripler E., Schwartz A., and N. Lazarovitch (2011) 
Sap flow measurements in date palm trees - a modified approach for water stress sensing. (2012). 
Tree Physiology 32 : 1171-8

Shapira O., Israeli Y., Shani U., and A. Schwartz (2012). 
Salt Stress Aggravates Boron Toxicity Symptoms in Banana Leaves by Impairing Guttation
Plant Cell and Environment 2012 doi: 10.1111/j.1365-3040.2012.02572.x

Botnick I., Xue W., Bar E., Schwartz A., Joel D., Fait A., E. Lewinsohn1 (2012) 
Distribution of primary and specialized metabolites in Nigella sativa seeds, a spice with vast traditional and historical uses
Molecules 2012, 17,10159-10177;doe:10.3390/molecules170910159

 

Sperling O., Lazarovitch N., Schwartz A., and O. Shapira (2012). 
The date palm tree's photosynthetic and photo-protective adaptation to water quality and environmental stresses in an arid climate 
(Submitted to J. Exp. Botany).

Erel R., Yermiyahu U., van Opstal J., Ben-Gal A., Schwartz A., and A. Dag (2012) 
Ramifications of tree nutritional status on flowering properties and productivity of olive (Olea europaea L.) trees
(Submitted to Tree Physiology).

Netzer1 Y., Shenker M., and A. Schwartz (2012) 
Effects of irrigation using treated wastewater on table grape vineyards: dynamics of sodium accumulation in soil and plant 
(Submitted to Irrigation Science)

 

Students

The students who conducted the experiments deserve all the credit:

Post Doc.:   Dr. Yishai Netzer    Or Shapira 

Ph.D.:   Ron Seligmann    Ran Arael    Or Sperling 

M.Sc.:   Idan Baht    Sarel Munitz    Dror Dotan    Yotam Zit    Yechiam Gets    Amit Haklai    David Yelin

 

Table and wine grapes: Dr. Yishai Netzer Post Doc., Idan Baht, Sarel Munitz and Dror Dotan M.Sc. students. 

Palm Dates: Or Sperling Ph.D. student, Avner Golan M.Sc. student (Fig. 8). 

Banana Plantations: Dr. Or Shapira Post Doc., Yotam Zit M.Sc. student 

Olives: Ran Arael Ph.D. Student. 

Citrus (grapefruits in the Galili): Yechiam Gets M.Sc. student 

Almonds: Amit Haklai M.Sc. student 

Avocado: David Yelin M.Sc. student 

Calcium transport: Ron Seligmann