Drought stress, biochemical, technological and phytopathological properties of faba bean Vicia faba L. samples

Бюллетень науки и практики / Bulletin of Science and Practice Т. 11. №7 2025

UDC 633:11: 547:9497                              

Global climate changes occurring in the modern world have led to a deterioration in the ecological situation on Earth, the development of stress factors such as drought and salinity, and the destruction of several valuable plant species. This may cause serious difficulties in meeting the future food demands of humanity. Therefore, one of the urgent tasks is to create new plant varieties and forms that are more productive and resistant to stress factors, including drought and salinity, by using various stress-resistant plant genotypes that can be cultivated under unfavorable soil and climate conditions. Considering the relevance of these issues, significant progress has been made in the Republic of Azerbaijan in the areas of genetic resource collection, study, documentation, restoration, and multiplication.

From a biological perspective, stress is considered any change in the external environmental conditions that weakens or negatively alters the normal development of a plant [1]. Biotic (pathogens, competition with other organisms, etc.) and abiotic (drought, salinity, radiation, high and low temperatures, etc.) stresses cause changes in the physiological activities of plants, weaken the biosynthesis processes occurring in cells, disrupt normal life processes, and ultimately can lead to the death of plants.

Currently, among the land areas used on Earth, drought, a natural stress factor, covers more than 26% of the total area. Drought stress, being one of the most widespread environmental factors affecting growth and productivity, induces various physiological, biochemical, and molecular responses in plants, and plants form tolerance mechanisms to adapt to unfavorable environmental conditions. The study of these mechanisms is of great theoretical and practical importance in the creation of plant varieties and forms resistant to adverse external environmental factors. This stress factor significantly harms agriculture by causing losses in crop productivity. Therefore, the search for and development of effective ways to increase the resistance of plants to various abiotic stresses (selection, agro-technical methods, etc.) is one of the important tasks facing the agricultural sector. The successful resolution of these issues is not possible without applying diagnostic methods and

Бюллетень науки и практики / Bulletin of Science and Practice Т. 11. №7 2025 techniques for plant resistance during the course of work. Plant resistance to stress characterizes the ability of plants to fully perform their life functions in unfavorable environmental conditions, and the degree of resistance ("weak," "strong") reflects the extent of this ability.

The degree of plant resistance to unfavorable environmental factors (such as drought, high temperature, salinity, etc.) can be determined by evaluating physiological parameters [2]. Since photosynthetic pigments are directly related to photosynthetic potential and primary productivity, the assessment of photosynthetic traits is of great importance in studying plant resistance to abiotic stresses. Photosynthetic pigments define plant activity and are dependent on various ecological factors. Therefore, determining them based on physiological indicators is of significant practical value. The pigment complex of a plant organism is sensitive to changes in environmental conditions. Abiotic stress factors such as drought, salinity, and high temperatures have a strong impact on the photosynthesis process. The study of these effects is crucial in clarifying the mechanisms of photosynthesis, investigating photosynthetic productivity, and determining the most suitable zones for planting specific plant varieties and samples in accordance with particular soil and climate conditions. One of the methods for using arid land areas for agricultural production purposes is the creation and cultivation of drought-resistant plants.

In order to meet the growing demand for food products, there is a need for legume varieties and samples that are resistant to environmental abiotic stress factors, stable, and have high productivity. Legumes are at the forefront of food technology development due to their nutritional significance. The fields of use and the role of leguminous plants in human life are vast, diverse, and significant. This diversity arises from the fact that these plants are rich in protein, essential amino acids, fats, vitamins, and minerals. For example, the seeds of these plants are rich in proteins and essential amino acids such as tryptophan, lysine, valine, threonine, phenylalanine, leucine, and isoleucine. Legumes are considered important plants.

As an example, we can mention the faba bean we studied. The faba bean is a versatile leguminous plant cultivated worldwide and is considered a good source of proteins, dietary fibers, and micronutrients [3, 4]. Additionally, it has been discovered that the plant is rich in bioactive compounds such as phenols, which are known for their antioxidant and antimicrobial properties [5].

The faba bean is a reliable source of various mineral elements such as potassium, calcium, sodium, and magnesium. Both the whole and peeled faba beans have been observed to be rich in microelements such as K, Ca, P, S, Mg, Cu, Zn, and Mn [6].

Iron and zinc in faba bean flour are significantly higher compared to wheat flour [7].

The mineral content in whole faba beans is higher compared to the peeled samples. The main component of faba beans is carbohydrates, which account for approximately 63%. Epidemiological studies show that legumes have a lower glycemic index compared to starchy foods such as potatoes and grains [8]. Amylose and amylopectin represent the main components of starch, which significantly influence the functional properties and digestibility of foods. Thus, due to their potential effects in the prevention and management of chronic conditions such as cancer, cardiovascular diseases, and obesity, the consumption of legumes is recommended [9].

The fat content of faba beans is relatively low compared to other plant-based protein sources; therefore, it can be classified as a low-fat food [6]. The fatty acid composition of faba bean oil, extracted using hexane, contains equal amounts of both saturated and unsaturated fatty acids. The main fatty acids are oleic and palmitic acids. A deficiency of amino acids essential for growth and development in living organisms leads to metabolic disorders and a range of diseases. The nutritional needs of individuals and animals are based not only on the protein content but also on the specific amounts of essential amino acids. Faba beans contain sulfur-containing amino acids such as cysteine and methionine in smaller amounts, while amino acids like leucine, lysine, tryptophan, and phenylalanine are found in higher quantities [11].

A characteristic feature of these plant proteins is their easy solubility in water and neutral salt solutions. The protein content in leguminous plant seeds is 2-3 times higher than in cereals. In environments where stress factors are present, achieving high productivity from agricultural crops is only possible through the use of plant varieties and forms that are resistant to changing environmental factors such as drought, salinity, and high temperatures.

Leguminous plants are not only important as a food source but also have significant agro-technical value. They enrich the soil with nitrogen through bacteria, which enhances its fertility. Additionally, legumes serve as precursors for many crops, which helps improve soil structure during crop rotation, reduce fertilizer costs, and contribute to the control of diseases and weeds [12].

The promotion of legume production and utilization plays a crucial role in ensuring food security, preserving agricultural sustainability, and protecting the environment. During development, plants actively interact with various environmental factors, including both abiotic (non-living) and biotic (living) components. Extreme ecological conditions, such as drought, salinity, heat, cold, and other stress factors, negatively affect plants [13].

The effects of drought primarily manifest as a reduction in the availability of free intracellular water, which leads to changes in the hydration of cytoplasmic proteins and disrupts the function of enzymatic proteins. In plants that are not adapted to drought, the intensity of respiration increases significantly during dehydration (likely due to an increase in sugar content, which acts as a respiratory substrate), and then gradually decreases. In drought-tolerant plants, no significant changes or only slight increases in respiration are observed under these conditions.

In the process of adaptation, the factors that create unfavorable conditions are essential as they ultimately help strengthen the plant's resistance and reduce the damage caused. To address these issues, it is necessary to apply stress-resistant methods and techniques and to determine the technical indicators of plant health, including their resistance to fungal and bacterial diseases.

Materials and methods

The subject of the research is the faba bean (Vicia faba L.) plant, and its drought resistance, along with a number of technical characteristics (e.g., protein content, lysine, moisture, 100-seed weight, cooking time, and seed water absorption capacity), as well as its physiological resistance to fungal, bacterial, and viral diseases, were studied.

In the flowering phase, the leaves of 15 faba bean samples were collected, and discs were obtained from them. The discs were placed in distilled water and a 20% sucrose solution for 24 hours. After 24 hours, the stressed discs were filtered, dried with filter paper, and then placed in 96% ethanol for 7 days. During this period, the chlorophyll from the leaf discs was transferred into the ethanol. The chlorophyll content was determined using a spectrophotometer (UV-3100PC) at two wavelengths (E665-E649). By comparing the percentage change in pigments (chl "a" and chl "b") in relation to the control, the stress-depression degree was calculated, and the degree of resistance of the samples to stress factors was determined. The less the pigment content changes under stress, the more resistant the samples are [14].

Additionally, a number of technological, quality, and biochemical indicators (100-seed weight, water absorption capacity, cooking time, color, moisture content, and the amounts of total nitrogen, lysine, and tryptophan (protein, Nx6.25)) were studied in the faba bean seed samples. The total nitrogen content was determined using the Kjeldahl method, lysine was measured using the method of A. S. Museyko and A. F. Siseyeva, and tryptophan was determined using the method of A. Ermakov and N. R. Yaroš [15].

Бюллетень науки и практики / Bulletin of Science and Practice Т. 11. №7 2025

Furthermore, a phytopathological evaluation was carried out on the faba bean samples, based on the natural background, in accordance with the balance system for fungal diseases and pest infestations.

Table 1

DETERMINATION OF THE DROUGHT STRESS RESISTANCE OF FABA BEAN SAMPLES

Sample name	Chlorophyll (a+b) content (μg per unit leaf area)
	Chlorophyll a+b		Change in chlorophyll content under drought, %	Stress depression level, %
	Control	Sucrose
Aze vifa-28	5,73	8,23	144,0	0
Aze vifa-64	5,04	7,11	141,0	0
Vifa-4-100	4,18	5,43	129,0	0
Vifa-8-98	4,88	5,92	121,0	0
Vifa-70	5,45	6,08	111,0	0
Aze vifa-60	5,0	5,36	107,0	0
Aze vifa-73	5,0	5,27	105,0	0
Aze vifa-71	4,73	4,96	105,0	0
Aze vifa-72	6,15	6,29	102,0	0
Aze vifa-3-95	6,54	6,37	97,0	3,0
Aze vifa-27	5,54	5,32	96,0	4,0
Aze vifa-62	5,19	4,59	88,4	11,6
Aze vifa-61	5,81	5,11	88,0	12,0
Aze vifa-63	6,15	5,06	82,0	18,0
Aze vifa-7-97	6,66	5,44	82,0	18,0

Results and discussion

Out of the 15 faba bean samples studied, 9 samples — Aze/VIFA-28, Aze/VIFA-60, Aze/VIFA-64, VIFA-70, VIFA-8-98, VIFA-4-100, Aze/VIFA-71, Aze/VIFA-72, Aze/VIFA-73 — were selected for their high drought tolerance. In these samples, the change in chlorophyll content due to drought ranged from 102.0% to 144.0%, with the chlorophyll stress-depression index being 0. Four of our samples (Aze VIFA-27, Aze VIFA-3-95, Aze VIFA-61, Aze/VIFA-62) were rated as drought-tolerant. The remaining samples were classified as moderately drought-tolerant. The protein content in our samples varied between 23.9% and 28.9%. The highest protein content was recorded in the samples Aze VIFA-64 (28.2%), Aze VIFA-60 (27.9%), and Aze VIFA-71 (27.7%). The lysine content ranged from 680 to 1198 (100 mg/g). The tryptophan content varied between 145 and 245 (100 mg/g). Based on the results of the analysis, the protein and lysine content were high in three samples (Aze VIFA-64, Aze VIFA-60, and Aze VIFA-71).

RESULTS OF TECHNOLOGICAL AND BIOCHEMICAL ANALYSES

OF FABA BEAN SEED SAMPLES

Table 2

Sample name	Seed Capacity ml	Cooking Time min	Color	Moisture %	100 Seeds g	Tryptophan mg/100 g	Lizin 100 mq/q	Protein %
Aze vifa -28	13	42	coffee	11,0	102,0	235	870	23,9
Aze vifa -60	14	42	coffee	11,0	102,0	180	1198	27,9
Aze vifa -70	14	40	coffee	11,8	104,0	180	680	23,9
Aze vifa-64	14	45	coffee	11,7	103,0	190	920	28,2
Aze vifa-8-98	10	55	coffee	10,3	102,0	245	755	25,3

Бюллетень науки и практики / Bulletin of Science and Practice Т. 11. №7 2025

Sample name      Seed Cooking Color Moisture 100 Tryptophan Lizin 100 Protein

Capacity Time              %     Seeds mg/100 g     mq/q      % ml      min                       g

Aze vifa-72          11        50     coffee     10,0     100,0      200        740       26,4

Aze vifa-71           11        55     coffee     10,8     100,0      210         885       27,7

Aze vifa-27          12        56     coffee     10,0     102,0      145         790       26,4

Aze vifa-4-100       13        50     coffee     10,0     100,0      235         888       26,8

Table 3 SAMPLES OF FABA BEAN PLANTS WITH HIGH RESULTS ACCORDING

TO TECHNOLOGICAL AND BIOCHEMICAL INDICATORS

Sample name Seed Capacity,     Cooking     100 Seeds, g Moisture, Tryptophan, Protein, % ml        Time, min                    %mg

Aze vifa-70           14             40           11,8         104,0         23523,9

Aze vifa-28           13             42           11,0         102,0         18023,9

Thus, among the 9 drought-resistant faba bean samples, 4 samples (Aze VIFA-60, Aze VIFA-64, Aze VIFA-71, Aze VIFA-4-100) were selected based on the results of biochemical analyses, which showed high values. These samples demonstrated high levels of protein and lysine. According to technological indicators, 3 samples showed good results in terms of 100-seed weight, water absorption capacity, cooking time, moisture content, and protein levels.

Table 4

RESULTS OF PHYTOPATHOLOGICAL EVALUATION OF FABA BEAN ( Vicia faba L.) PLANTS INFECTED WITH VARIOUS FUNGAL DISEASES

Sample Variety Name Place of Origin Number Number of Diseased Disease Name  Disease

	of Plants	Plants			Resistance
		sayı faizlə	balla
Aze vifa -28	19	-         -	0	-	immun
Aze vifa-60	21	-         -	0	-	immun
VİFA-4-100	19	-         -	0	-	immun
Aze vifa-73	21	-         -	0	-	immun

Additionally, 4 (Aze vifa -28, Aze vifa-60, VİFA-4-100, Aze vifa-73) of the drought-resistant plant samples showed high results in the phytopathological evaluation. These samples demonstrated high resistance to fungal, bacterial, and viral diseases, surpassing the standard in terms of productivity characteristics, and were selected as the most promising forms.

Results

Thus, as a result of the conducted research, drought-resistant samples of the faba bean plant were identified. Their biochemical composition was studied, and samples with high levels of protein and essential amino acids were selected. Technological parameters and phytopathological evaluations were also conducted, indicating that these samples are suitable for use as donor plants in future selection efforts.