The water loss phenotype of isolated plant leaves and its water loss rate are two important physiological indexes for the study of drought tolerance traits in plants. Through this experiment, students will learn to master the principles and methods of observing the water loss phenotype of isolated plant leaves and determining their water loss rate.
Operation method
Observations on the water loss phenotype of isolated leaves of plants and experiments on the determination of their water loss rate
Principle
The main organ of plant water dissipation is the leaf, which in turn is mainly through stomata. Therefore, the water loss of isolated leaves largely reflects the water status of the whole plant. When isolated leaves are exposed to air, due to water diffusion without timely replenishment, the leaves will develop a wilting phenotype, which is aggravated with the extension of time. At the same time, the degree of water loss (water loss rate) of leaves at different times can be quantified by weighing. Different plants, different species of the same plant, and different stages of growth and development have different water loss of leaves. Generally, the drought resistance of plants is negatively correlated with the water loss status of isolated leaves. We can identify the drought resistance of plants by observing the water loss phenotype of isolated leaves and determining their water loss rate. In this experiment, we used the model plant Arabidopsis thaliana as the material, and selected two materials with obvious differences in drought resistance, the wild type (Col) and the drought-resistant mutant (lew2-1), to carry out comparative experiments, to observe the water loss phenotypes and the differences in water loss rates of their isolated leaves, and to analyze and compare their drought resistance.
Materials and Instruments
Arabidopsis wild-type (Col) seedlings Mutant lew2-1 seedlings Move I. Experimental steps For more product details, please visit Aladdin Scientific website.
Small scissors Small tweezers Petri dishes Electronic balance
1. Observation of water loss phenotype of isolated leaves
Two leaves were cut with small scissors and tweezers from two types of seedlings, Arabidopsis wild type (Col) and mutant lew2-1, and placed in the same petri dish. The water loss phenotypes of the leaves describing both were recorded after about 2-3 h of waiting for the leaves to develop a chlorotic phenotype.
2. Determination of water loss in isolated leaves
First, the two pieces of weighing paper were weighed separately. Ten leaves were clipped with small scissors and tweezers from two types of seedlings of Arabidopsis wild type (Col) and mutant lew2-1, respectively, and placed on the weighing paper to be weighed separately. They were then placed in two petri dishes along with their respective weighing papers, after which they were reweighed at three time intervals of 1. 2. 3 h, respectively, and the results were recorded.
II. Experimental results
3. Comparison of water-loss phenotypes of isolated leaves: The phenotypic conditions of Arabidopsis wild-type (Col) and mutant lew2-1 seedlings before and after water loss in isolated leaves were compared.
4. Plotting line graphs of water loss rate of isolated leaves: The water loss rates of isolated leaves of Arabidopsis wild type (Col) and mutant lew2-1 seedlings were calculated before and after 1, 2, and 3 h of water loss, respectively, and then line graphs were made to analyze and compare the water loss of isolated leaves of the two types of seedlings. 
W1: weight of isolated leaves before water loss
W2: weight of isolated leaves after 1 or 2 or 3 hours of water loss.