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Mailing Address:
The Robert H. Smith Institute of
Plant Sciences and Genetics
in Agriculture
POB 12, Rehovot 76100, Israel

Administrator: Neomi Maimon 
Tel: 972-8-948-9251,
Fax: 972-8-948-9899,
E-mail: neomim@savion.huji.ac.il

Director: Prof. David Weiss
Tel: 972-8-948-9436
Fax: 972-8-948-9899
E-mail: david.weiss@mail.huji.ac.il

 

tags

Negin, B. ; Yaaran, A. ; Kelly, G. ; Zait, Y. ; Moshelion, M. Mesophyll ABA restrains early growth and flowering but does not directly suppress photosynthesis. Plant Physiol 2019.Abstract
Abscisic acid (ABA) levels increase significantly in plants under stress conditions and ABA is thought to serve as a key stress-response regulator. However, the direct effect of ABA on photosynthesis and the effect of mesophyll ABA on yield under both well-watered and drought conditions are still the subject of debate. Here, we examined this issue using transgenic Arabidopsis thaliana plants carrying a dominant ABA-signaling inhibitor under the control of a mesophyll-specific promoter (FBPase::abi1-1, abbreviated to fa). Under normal conditions, fa plants displayed slightly higher stomatal conductance and carbon assimilation than wild-type (WT) plants; however, these parameters were comparable following ABA treatment. These observations suggest that ABA does not directly inhibit photosynthesis in the short term. fa plants also exhibited a variety of altered phenotypes under optimal conditions, including more vigorous initial growth, earlier flowering, smaller flowers and delayed chlorophyll degradation. Furthermore, under optimal conditions, fa plant seed production was less than a third of that observed for the WT. However, under drought conditions, WT and fa seed yields were similar due to a significant reduction in WT seed and no reduction in fa seed. These findings suggest that endogenous basal ABA inhibits a stress-escape response under non-stress conditions, allowing plants to accumulate biomass and maximize yield. The lack of a correlation between flowering time and plant biomass combined with delayed chlorophyll degradation suggests that this stress-escape behavior is regulated independently and upstream of other ABA-induced effects such as rapid growth and flowering.
Yaaran, A. ; Negin, B. ; Moshelion, M. Role of guard-cell ABA in determining steady-state stomatal aperture and prompt vapor-pressure-deficit response. Plant Sci 2019, 281, 31-40.Abstract
Abscisic acid (ABA) is known to be involved in stomatal closure. However, its role in stomatal response to rapid increases in the vapor pressure deficit (VPD) is unclear. To study this issue, we generated guard cell-specific ABA-insensitive Arabidopsis plants (guard-cell specific abi1-1; GCabi). Under non-stressed conditions, the stomatal conductance (g) and apertures of GCabi plants were greater than those of control plants. This supports guard-cell ABA role as limiting steady-state stomatal aperture under non-stressful conditions. When there was a rapid increase in VPD (0.15 to 1 kPa), the g and stomatal apertures of GCabi decreased in a manner similar that observed in the WT control, but different from that observed in WT plants treated with fusicoccin. Low VPD increased the size of the stomatal apertures of the WT, but not of GCabi. We conclude that guard-cell ABA does not play a significant role in the initial, rapid stomatal closure that occurs in response to an increase in VPD, but is important for stomatal adaptation to ambient VPD. We propose a biphasic angiosperm VPD-sensing model that includes an initial ABA-independent phase and a subsequent ABA-dependent steady-state phase in which stomatal behavior is optimized for ambient VPD conditions.

Books

New books by Professor Zamski

coverelizamski

Scientific Publications

Publications:

Dissertation

  1. Zamski, E. 1967. M.Sc. Thesis. Factors influencing the formation of resin ducts and resin secretion in Pinus_ halepensis Mill. Hebrew University of Jerusalem.
  2. Zamski, E. 1971. Ph.D. Thesis. Factors influencing the formation ofresin ducts and resin secretion in Pinus_ halepensis Mill. Hebrew University of Jerusalem.

Books

Publications

Selected Publications

  1. Sheinberg O., Rabinowitch H.D., Rubin B. & Tel-Or E., 1999 Adjustment to low light intensity enhances susceptility of bean leaves to oxidative stress. J. Plant Physiol. 155:393-398
  2. Butow B.J., Wynne D., Tel-Or E., 1997 Antioxidative protection of Peridinium gatunense in Lake Kinneret: Seasonal and daily variation. J Phycol 33: (5) 780-786

Special Interests and Achievments

  • Basic genetics and physiology studies of the spontaneous mutations of ripening inhibitor genes in tomatoes and the consequent exploitation of the knowledge resulted in the original development of long shelf-life tomatoes, thus revolutionizing the fresh market industry.

NisuyWin

NisuyWin Version 4.0 Download information

NisuyWin is a Windows version of the old DOS program "Nisuy". This program computes Analysis of Variance and Multiple Range tests. It is specially adapted for analyzing agricultural field experiments, but it can also be used for other types of experiments. "NisuyWin" is the English version, for details about downloading the Hebrew version of the program read below.

Cotton2K Model

Cotton2K Model version 4.0

A. Marani

Version history

The COTTON2K cotton simulation model is descended from GOSSYM-COMAX. Its main purpose was to make the model more useful for conditions of cotton production under irrigation in the arid regions of the Western USA. Since many changes have been made in the model, it has been given a new name: CALGOS (for CALifornia GOSsym). The present version, which is completely revised has been renamed COTTON2K.

Research Abstracts

Abstracts of Publications (2005-2014)

Brown JK, Lambert GM, Ghanim M, Czosnek H and Galbraith DW (2005).
Nuclear DNA Content of the Whitefly Bemisia tabaci (Genn.) (Aleyrodidae: Homoptera/ Hemiptera) Estimated by Flow Cytometry. Bulletin of Entomological Research. 95:309-312.