Abstract
Water deficiency is one of the most important abiotic factors limiting the growth and productivity of plants. Under conditions of water deficiency, plants can synthesize osmoprotectors, in particular proline. The aim of our work was to estimate the accumulation of free proline in the leaves of two poplar clones ‘Slava Ukrainy’, ‘Guliver’ and willow clone ‘Pechalna’ in water-deficient conditions. Plants were grown outdoors, providing protection from the rain with a plastic wrap, with a differentiated watering: normal watering –100% (control) and water deficit – 75%, 50 % and 25% moisture by volume from the control. The content of free proline was determined by a modified Bates method by measuring the optical density of the ninhydrin-proline solution on a spectrophotometer at a wavelength of 520 nm. Experimental observations have shown that the total content of proline differs among poplar and willow clones. The poplar ‘Guliver’ had a lower content of proline compared to the poplar ‘Slava Ukrainy’ and the willow ‘Pechalna’. The level of free proline also differed between the samples of poplar ‘Guliver’ in the first and second years of growth under water deficiency. However, on the 30th day of treatment we did not find any differences in the content of proline between the stressed and control plants. Thus, the clone factor has the only obvious effects on proline content while the factor of water regime showed no effects on the level of proline. We hypothesize that water deficiency is more likely to alter proline levels as a shorter time response to stress than the terms we applied.
Highlights
Fast-growing poplar and willow trees are plants belonging to the widespread Salicaceae family consisting of many species and play an important role in wood and biofuel production, public services, environmental protection, soil health, and afforestation of degraded soils (Kutsokon et al, 2017; Sklyarenko & Bessonova, 2018)
The total content of proline differs among the clones of poplars and willow as well as in the samples of the first and second year trees of poplar (Table 1)
The lowest proline content was determined in the summarised samples of poplar ‘Guliver’ in the second growing season which significantly differed from all other samples (13.68 μg/mL, P < 0.05)
Summary
Fast-growing poplar and willow trees are plants belonging to the widespread Salicaceae family consisting of many species and play an important role in wood and biofuel production, public services, environmental protection, soil health, and afforestation of degraded soils (Kutsokon et al, 2017; Sklyarenko & Bessonova, 2018). There is a great opportunity to realize economic and environmental benefits via creation of short-rotation plantations of these trees on land unsuitable for annual crop production. This will avoid public concern about the displacement of arable land from food to bioenergy production (Kharytonov et al, 2017; Kutsokon et al, 2020). Differences in drought adaptation among the poplars are found at a variety of levels of organization, including the genetic, morphological, physiological, and biochemical responses of the plant (Guo et al, 2010)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
