Application of trimethylamine oxide in improving drought resistance of apple stock

Abstract

The invention relates to the technical field of planting, and particularly discloses application of trimethylamine oxide to improvement of drought resistance of apple rootstocks. Trimethylamine oxide (TMAO) is beneficial to growth and development of apple plants and especially has a remarkable effect on the apple rootstocks, and trimethylamine oxide (TMAO) is used for improving photosynthesis of the apple rootstocks under drought stress, so that the drought resistance of the apple rootstocks is improved. Therefore, the drought resistance of the apple stock is improved. The chemical structural formula of the trimethylamine oxide is shown in the specification.

Description

Technical Field

[0001] This invention relates to the field of plant cultivation technology, specifically to the use of trimethylamine oxide in improving the drought resistance of apple rootstocks. Background Technology

[0002] Plants, due to their sessile growth characteristics, are exposed to a variety of environments over long periods. Their survival is particularly challenging when faced with adverse environmental stresses such as extreme temperatures, water deficits, or high-salt soils. To maintain survival and reproduction under stress, plants initiate a series of adaptive responses, ranging from rapid physiological protection mechanisms (such as the accumulation of osmotic regulators) to developmental adjustments (such as increasing the root / above-ground biomass ratio), ultimately enhancing their stress tolerance.

[0003] Drought is a major factor restricting fruit yield and quality. In recent years, the intensified global greenhouse effect has further exacerbated climate drought, thus severely limiting the healthy development of the fruit industry. The drought environment causes uneven flowering and severe flower drop during the budding stage; hindered fruit enlargement during the fruit-setting stage, resulting in small fruit with poor quality; and exacerbates physiological diseases, pests, and viral diseases during the growing season. Drought stress not only reduces orchard yield in the current year but also affects flower bud formation in the following year, causing significant harm to fruit growers.

[0004] Apples are one of the world's four major fruit trees and the most widely cultivated deciduous tree species in temperate zones. The Loess Plateau is my country's largest and best apple-growing region; however, its arid climate severely restricts the development of the local apple industry. Therefore, it is necessary to explore ways to improve the drought resistance of apple trees. Summary of the Invention

[0005] To explore a way to improve the drought resistance of apple trees, this invention provides the use of trimethylamine oxide (TMAO) in improving the drought resistance of apple rootstocks. The TMAO provided by this invention is beneficial to the growth and development of apple plants, especially to the M26 apple rootstock. Under drought stress, TMAO is used to improve the photosynthesis, leaf water content, and root-to-shoot ratio of M26, thereby enhancing its drought resistance.

[0006] This invention provides the use of trimethylamine oxide in improving the drought resistance of apple rootstocks, wherein the chemical structural formula of trimethylamine oxide is as follows: .

[0007] The trimethylamine oxide (TMAO) provided by this invention is beneficial to the growth and development of apple plants, especially to the apple rootstock M26. Under drought stress, TMAO enhances photosynthesis, leaf water content, and root-to-shoot ratio in M26, thereby improving its drought resistance. TMAO also increases plant height, root length, leaf fresh weight, and leaf water content in M26 under drought stress, thus improving the survival rate of M26 plants under drought stress.

[0008] Furthermore, the effective concentration of the trimethylamine oxide is 0.5 mM to 2.5 mM.

[0009] Furthermore, the effective concentration of the trimethylamine oxide is 0.5 mM to 1.0 mM.

[0010] Further, the application is as follows: prepare a trimethylamine oxide solution with a concentration of 0.5mM to 2.5mM, and irrigate it onto apple rootstock seedlings at a volume of 100mL to 200mL.

[0011] Furthermore, the trimethylamine oxide is used to promote photosynthesis in apple rootstocks under drought conditions, thereby increasing leaf water content and root-to-shoot ratio.

[0012] Furthermore, the trimethylamine oxide is used to improve the plant height, root length, leaf fresh weight, and leaf water content of apple rootstocks under drought stress.

[0013] Furthermore, the trimethylamine oxide is used to improve the survival rate of apple rootstocks under drought stress.

[0014] Furthermore, the apple rootstock is apple dwarfing rootstock M26.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention provides a novel use for trimethylamine oxide (TMAO), revealing that TMAO can promote root development in plants, particularly the apple rootstock M26, increase photosynthesis, leaf water content, and root-to-shoot ratio under drought stress, thereby enhancing the drought resistance of M26. This significantly promotes the development of new productivity in the apple industry in arid regions.

[0016] Trimethylamine oxide (TMAO) is a typical protein stability osmotic regulator, generated from flavin-containing monooxygenases (FMOs) through the N-oxidation of trimethylamine (TMA). It acts as a molecular chaperone to maintain the folded state of proteins and resist the effects of denaturing agents such as pH, urea, high pressure, high salt, and low temperature. This study selected M26, a commonly used rootstock in apple production, as the experimental material. Different concentrations of TMAO (0, 0.5, 1.0, and 2.5 mM) were applied to the roots. After 30 days, short-term natural drought treatment and a 60-day long-term moderate drought treatment were conducted. The results showed that TMAO improved the survival rate of M26 under short-term drought stress, promoted root development and leaf photosynthetic efficiency, and enhanced the drought resistance of M26. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 The effects of TMAO on the growth and development of apple rootstock M26 under long-term drought stress; In the figure, A represents the phenotype of M26 under normal water supply and long-term drought stress; B represents the plant height of M26 under normal water supply and long-term drought stress; C represents the stem diameter of M26 under normal water supply and long-term drought stress.

[0019] Figure 2 The effect of TMAO on root growth of apple rootstock M26 under long-term drought stress; In the figure, A represents the root phenotype of M26 under normal water supply and long-term drought stress; B represents the root length of M26 under normal water supply and long-term drought stress.

[0020] Figure 3 The effect of TMAO on biomass accumulation in apple rootstock M26 under long-term drought stress; In the figure, A represents the effect of TMAO on the aboveground dry weight of apple rootstock M26 under long-term drought stress; B represents the effect of TMAO on the root dry weight of apple rootstock M26 under long-term drought stress. C represents the effect of TMAO on the root-to-shoot ratio of apple rootstock M26 under long-term drought stress.

[0021] Figure 4The effect of TMAO on leaf water content of apple rootstock M26 under long-term drought stress; In the figure, A represents the effect of TMAO on the fresh weight of leaves of apple rootstock M26 under long-term drought stress; B represents the effect of TMAO on the dry weight of leaves in apple rootstock M26 under long-term drought stress. C represents the effect of TMAO on the leaf water content of apple rootstock M26 under long-term drought stress.

[0022] Figure 5 The effect of TMAO on photosynthesis in apple rootstock M26 under long-term drought stress; In the figure, A represents the effect of TMAO on the net photosynthetic rate of apple rootstock M26 under long-term drought stress; B represents the effect of TMAO on the stomatal conductance of apple rootstock M26 under long-term drought stress. C represents the effect of TMAO on intercellular CO2 concentration in apple rootstock M26 under long-term drought stress; D represents the effect of TMAO on the transpiration rate of apple rootstock M26 under long-term drought stress.

[0023] Figure 6 The effect of TMAO on chlorophyll fluorescence in apple rootstock M26 under long-term drought stress.

[0024] Figure 7 The effects of TMAO on apple rootstock M26 under short-term natural drought stress; In the figure, A represents the phenotypic changes of M26 during natural drought; B represents the survival rate of M26 after a short period of natural drought.

[0025] Figure 8 The effect of TMAO on photosynthesis in apple rootstock M26 under short-term natural drought stress; In the figure, A represents the effect of TMAO on the net photosynthetic rate of apple rootstock M26 under short-term natural drought stress; B represents the effect of TMAO on intercellular CO2 concentration in apple rootstock M26 under short-term natural drought stress. C represents the effect of TMAO on stomatal conductance of apple rootstock M26 under short-term natural drought stress. D represents the effect of TMAO on the transpiration rate of apple rootstock M26 under short-term natural drought stress. Detailed Implementation

[0026] The specific embodiments of the present invention are described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise specified, the experimental methods described in the embodiments of the present invention are conventional methods, and the materials and reagents used in the following embodiments are commercially available unless otherwise specified.

[0027] Example 1: The use of trimethylamine oxide in improving the drought resistance of apple rootstock M26.

[0028] I. Materials and Methods 1. Experimental Materials and Methods The plant material used in this invention is M26, a commonly used apple dwarfing rootstock in production. The plant material was provided by the Wuquan Comprehensive Experimental Station of Northwest A&F University.

[0029] 2. Experimental Methods (1) Trimethylamine oxide (TMAO) treatment: M26 tissue culture seedlings with a growth period of one month were transplanted into a greenhouse. Plant materials with relatively uniform growth vigor were selected. After new leaves emerged, TMAO concentrations of 0 mM, 0.5 mM, 1.0 mM and 2.5 mM were applied. One month later, apple seedlings with relatively uniform growth vigor were selected again and subjected to short-term natural drought and long-term moderate drought treatment.

[0030] Short-term natural drought treatment: One-month-old M26 tissue culture apple seedlings were transplanted into the experimental station's greenhouse. After a month of recovery, water was withheld for natural drought treatment. After 10 days of natural drought, the seedlings were re-watered, and the survival rate was recorded one week later. Phenotypic data were taken and recorded before drought, 7 days after drought, and after re-watering.

[0031] Long-term drought treatment: A combination of TDR soil moisture meter and gravimetric method was used for quantitative water control. Control group: TDR measured soil volumetric water content of 43%–48%, and gravimetric method measured soil water content of 70%–100%.

[0032] Long-term moderate drought treatment group: Soil volumetric water content measured by TDR was 18%–23%, and soil water content measured by gravimetric method was 35%–50%. The calculation method for soil water content by gravimetric method is: Soil water content = (soil fresh weight - soil dry weight) / (soil saturated weight - soil dry weight). Water control treatment was maintained for 2 months.

[0033] Photosynthetic index determination: The photosynthetic index of the plants was determined using a LI-COR6400 photosynthetic meter, including net photosynthetic rate, stomatal conductance, intercellular CO2 concentration and transpiration rate.

[0034] Chlorophyll fluorescence measurement: Chlorophyll fluorescence parameters Fv / Fm were measured using a pulse-modulated chlorophyll fluorometer.

[0035] Leaf moisture content determination: Weigh the fresh weight of the leaves using a balance with a strength of 0.01%, then soak them in water overnight to allow them to absorb water (saturated weight), and finally dry them to determine the dry weight. Leaf moisture content = (fresh weight of leaves - dry weight of leaves) / (saturated weight of leaves - dry weight of leaves).

[0036] II. Results and Analysis 1. Trimethylamine oxide (TMAO) enhances biomass accumulation of M26 under prolonged drought stress. Apple rootstock M26 seedlings of uniform growth, one month old, were used as experimental materials. Different concentrations of trimethylamine oxide (TMAO) (0 mM, 0.5 mM, 1.0 mM, 2.5 mM) were applied at 100 ml per seedling for one month. Following this, a two-month prolonged drought treatment was initiated. The control group received normal irrigation (maintaining soil moisture at field capacity, approximately 500 ml / pot), while the treatment groups received moderate irrigation to maintain moderate soil drought (maintaining soil moisture at 50% field capacity, approximately 200 ml / pot). Plants were observed after two months, and the results are as follows: Figure 1 As shown, different concentrations of TMAO treatment all promoted the growth of M26 to some extent, specifically, the plant height was significantly higher than that of the control without TMAO treatment.

[0037] Analysis of root development revealed the following results: Figure 2 As shown, drought treatment significantly inhibited root development of M26, but different concentrations of TMAO treatment alleviated the inhibitory effect of drought to some extent.

[0038] The biomass of the aboveground parts and roots of M26 was statistically analyzed, and the results are as follows: Figure 3 As shown, different concentrations of TMAO treatment all increased the aboveground biomass and root biomass of M26 under drought stress to some extent; drought stress promoted the increase of the root-to-shoot ratio of the plant, while TMAO treatment made the root-to-shoot ratio of M26 higher than that of the untreated plant.

[0039] 2. Trimethylamine oxide (TMAO) increases leaf water content of M26 under prolonged drought stress. The ability to maintain leaf water content under drought conditions is an important criterion for evaluating crop drought resistance, directly reflecting the water saturation state of plant tissues. When soil drought hinders root water absorption, a decrease in leaf water content is one of the earliest detectable physiological responses, and the magnitude of this decrease is positively correlated with the severity of stress. Therefore, maintaining normal leaf water content is one of the abilities of drought-resistant plants to resist stress.

[0040] The results are as follows Figure 4As shown, prolonged drought stress significantly reduced the fresh weight, dry weight, and leaf water content of M26 leaves. However, treatments with different concentrations of TMAO alleviated the trend of decreasing leaf water content in M26 under drought stress, indicating that TMAO can improve the drought resistance of M26.

[0041] 3. Trimethylamine oxide (TMAO) improves the photosynthetic efficiency of M26 under long-term drought stress. Under drought stress, plant stomata close, stomatal conductance decreases, and net photosynthetic rate and transpiration rate are also inhibited. The ability of plants to maintain photosynthetic efficiency under drought stress is also an important indicator of their drought resistance. Our results show that under normal water supply conditions, the photosynthetic indices of M26 (net photosynthetic rate, stomatal conductance, intercellular CO2 concentration, and transpiration rate) are not affected by TMAO treatment; however, under long-term drought stress, the photosynthetic capacity of M26 is inhibited (net photosynthetic rate, stomatal conductance, and transpiration rate), while the difference in intercellular CO2 concentration is not significant. Different concentrations of TMAO treatment alleviated the photosynthetic inhibition of M26 under drought stress, meaning that the net photosynthetic rate, stomatal conductance, and transpiration rate were all higher than the control without TMAO treatment. Figure 5 ).

[0042] However, the chlorophyll fluorescence detection results showed that, regardless of whether drought treatment was performed, different concentrations of TMAO had no significant effect on the chlorophyll fluorescence of M26 leaves. Figure 6 ).

[0043] 4. Trimethylamine oxide (TMAO) improves the survival rate of M26 under natural drought stress. M26 plants treated with different concentrations of TMAO were irrigated until the soil was saturated, and then watering was stopped. Before the drought, TMAO treatment did not significantly affect the growth of M26. One week after watering was stopped, the growth of M26 plants treated with different concentrations of TMAO was observed to be better than that of the control. After watering was stopped for 10 days, watering was resumed, and the survival of the plants was observed. It was found that the short-term natural drought caused about 40% of the M26 plants to die, while the survival rate of M26 plants treated with 0.5 mM TMAO increased the survival rate to about 60%, and the survival rate of plants treated with 1.0 mM TMAO increased the survival rate to 65%. Figure 7 The above results indicate that TMAO can improve the drought resistance of apple rootstock M26.

[0044] 5. Trimethylamine oxide (TMAO) improves the photosynthetic efficiency of M26 under natural drought stress. Drought stress significantly reduced the net photosynthetic rate, intercellular CO2 concentration, stomatal conductance, and transpiration rate of M26 cells. Figure 8It was found that before the drought, different concentrations of TMAO treatment did not significantly affect the photosynthetic indicators of M26. However, one week after the water supply was stopped, the net photosynthetic rate, intercellular CO2 concentration, and stomatal conductance of M26 treated with different concentrations of TMAO were all better than those of the control treatment. However, the transpiration rate of M26 treated with different concentrations of TMAO was lower than that of the control treatment. These results indicate that TMAO treatment can improve the photosynthetic performance of apple rootstock M26 under drought stress.

[0045] Although preferred embodiments of the invention have been described, those skilled in the art, once they have learned the basic inventive concept, can make other changes and modifications to these embodiments.

[0046] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. The use of trimethylamine oxide in improving the drought resistance of apple rootstocks, characterized in that, The chemical structural formula of the trimethylamine oxide is as follows: 。 2. The use of trimethylamine oxide according to claim 1 in improving the drought resistance of apple rootstock, characterized in that, The effective concentration of the trimethylamine oxide is 0.5 mM to 2.5 mM.

3. The use of trimethylamine oxide according to claim 2 in improving the drought resistance of apple rootstock, characterized in that, The effective concentration of the trimethylamine oxide is 0.5 mM to 1.0 mM.

4. The use of trimethylamine oxide according to claim 1 in improving the drought resistance of apple rootstock, characterized in that, The application involves preparing a 0.5mM to 2.5mM trimethylamine oxide solution and watering it onto apple rootstock seedlings at a rate of 100mL to 200mL.

5. The use of trimethylamine oxide according to claim 1 in improving the drought resistance of apple rootstock, characterized in that, The trimethylamine oxide is used to promote photosynthesis in apple rootstocks under arid conditions, and to increase leaf water content and root-to-shoot ratio.

6. The use of trimethylamine oxide according to claim 1 in improving the drought resistance of apple rootstock, characterized in that, The trimethylamine oxide is used to improve the plant height, root length, leaf fresh weight, and leaf water content of apple rootstocks under drought stress.

7. The use of trimethylamine oxide according to claim 1 in improving the drought resistance of apple rootstock, characterized in that, The trimethylamine oxide is used to improve the survival rate of apple rootstocks under drought stress.

8. The use of trimethylamine oxide according to claim 1 in improving the drought resistance of apple rootstock, characterized in that, The apple rootstock is apple dwarfing rootstock M26.

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