Common Mistakes in Drought Experiment Set Up

Examining crop response to drought is one of the most popular experiments in plant stress physiology. This is most likely due to its importance and relevance as it pertains to global warming and concerns about food security.

Wild Barley drought

Surprisingly, despite the fact that drought experiments are so popular, our understanding of how to improve crop productivity under stress is still very limited. In fact, very few commercial drought tolerant lines are released - significantly less than lines which are disease tolerant or resistant.  

Why is this so?

Perhaps it is related to the fact that drought testing of a plant is very easy to implement, just close the tap, but very difficult to analyze. The most popular experiment simply involves the selection of the healthiest looking plants as the days with no irrigation continue to pass. However, this approach reveals which plants are good survivors; NOT the good producer plants, NOT the most tolerant plants and definitely NOT the most resistant crops.

The important point to remember here is that plants lose water (via transpiration) at surprisingly high rates. Actually, a plant is capable of losing its own weight in less than a day under normal growth conditions (e.g. young tomato, 8-12 weeks old can transpire 1-2 liters of water per day!). These figures should be taken into account in the design of the experiment.

Moreover, if we expose several plants to drought (this is true of any plant), initially under relatively high soil moisture, the following occurs: plants with a slightly higher transpiration rate (say 10% more than average) will be exposed to a much faster soil water reduction rate. Consequently, they are exposed to limiting water conditions (stress) a few days earlier than the other plants. The opposite occurs with plants with a marginally lower transpiration rate - they will have fairly good soil water content for longer periods than the average plant.

That’s why screening plants by simple observation and selecting the healthier looking ones, leads us to err twice:

  1. We select the plants which were not (or significantly less) stressed due to their lower transpiration as they did not face the same severity of soil drought as the higher transpiring plants (we are actually comparing a different treatment!).
  2. We select plants which are probably less productive (transpiration is linearly correlated with yield).

Is there a solution? Indeed there is! All you need do is continuously and simultaneously measure multiple plants and their ambient conditions (soil and atmosphere). We call it Functional (Physiological) Phenotyping. It is a phenotyping technique that characterizes the plant reaction to specific environmental conditions and provides a detailed physiological profile.


Functional phenotyping can be used to COMPARATIVELY select the best performing plants under specific conditions or to better understand the biological mechanisms controlling their response. The accuracy of functional phenotyping enables the detection of small changes in specific physiological traits associated with environmental changes. The accompanying statistical analysis provides powerful tools for the selection of plants that exhibit desired behavior in relation to control plants.

Want to know more? Contact our experts.


Academic Articles

  1. The following selected scientific papers used Plant-DiTech technology:
  2. The tomato DELLA protein PROCERA acts in guard cells to promote stomatal closure

    Nir et. Al., (2017) Plant Cell DOI:10.1105/tpc.17.00542
  3. Transcriptome analysis of Pinus halepensis under drought stress and during recovery
    Fox et. Al., (2017) Tree Physiology DOI:10.1093/treephys/tpx137

  4. A combination of stomata deregulation and a distinctive modulation of amino acid metabolism are associated with enhanced tolerance of wheat varieties to transient drought
    Aidoo et. al., (2017) Metabolomics DOI:10.1007s11306-017-1267-y

  5. High-throughput physiological phenotyping and screening system for the characterization of plant–environment interactions
    Halperin et. Al., (2016) The Plant Journal 10.1111/tpj.13425

  6. Cytokinin activity increases stomatal density and transpiration rate in tomato
    Faber et. Al., (2016) Journal of Experimental Botany DOI: 10.1093/jxb/erw398
  7. The advantages of functional phenotyping in pre-field screening for drought-tolerant crops
    Negin et. al., (2016)  Functional Plant Biology  DOI: 10.1071/FP16156
  8. Current challenges and future perspectives of plant and agricultural biotechnology
    Moshelion and Altman, (2015) Trends in Biotechnology. 33, 337–342
  9. Growth and physiological responses of isohydric and anisohydric poplars to drought
    Ziv Attia et al., (2015) Journal of Experimental Botany doi10.1093jxberv195

  10. Expression of Arabidopsis Hexokinase in Citrus Guard Cells Controls Stomatal Aperture and Reduces Transpiration
    Lugassi et. al., (2015) Frontiers in plant sciences DOI:10.3389/fpls.2015.01114.

  11. Natural variation and gene regulatory basis for the responses of asparagus beans to soil drought
    Xu et. al., (2015) Frontiers in plant sciences DOI: 10.3389/fpls.2015.00891
  12. Mesophyll photosynthesis and guard cell metabolism impacts on stomatal behaviour
    Tracy Lawson et. al., (2014) New Phytologist DOI: 10.1111nph.12945
  13. Transcriptome sequencing of two wild barley (Hordeum spontaneum L.) ecotypes differentially adapted to drought stress reveals ecotype-specific transcripts
    Bedada et. al., (2014) BMC Genomics DOI: 10.11861471-2164-15-995
  14. Role of aquaporins in determining transpiration and photosynthesis in water-stressed plants: crop water-use efficiency, growth and yield.
    Moshelion  et. al., (2014) Plant Cell & Environment DOI: 10.1111/pce.12410
  15. Relationship between hexokinase and the aquaporin PIP1 in the regulation of photosynthesis and plant growth
    Kelly et. al.,  (2014) PLoS One. 9 : DOI:10.1371/ journal.pone.0087888
  16. The Arabidopsis gibberellin methyl transferase 1 suppresses gibberellin activity, reduces whole-plant transpiration and promotes drought tolerance in transgenic tomato.
    Nir et. al., (2013) Plant cell and Environment 37, 113–123
  17. Hexokinase mediates stomatal closure
    Kelly et. al.,  (2013) The Plant Journal 75, 977–988 DOI: 10.1111/tpj.12258
  18. Risk-taking plants: Anisohydric behavior as a stress-resistance trait
    Sade et. Al., (2012) Plant Signaling & Behavior DOI org/10.4161/psb.20505
  19. Development of synchronized, autonomous, and self-regulated oscillations in transpiration rate of a whole tomato plant under water stress
    Wallach et. al., (2010) Journal of Experimental Botany 61:3439–3449
  20. The Role of Tobacco Aquaporin1 in Improving Water Use Efficiency, Hydraulic Conductivity, and Yield Production Under Salt Stress
    Sade et. al., (2010) Plant Physiology 152:1-10
  21. Improving plant stress tolerance and yield production: is the tonoplast aquaporin SlTIP2;2 a key to isohydric to anisohydric conversion?
    Sade et. al., (2009) New Phytologist. 181: 651–661

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