Application of syringic acid in promoting tobacco root growth

Abstract

The application of eugenol in promoting plant root growth: The eugenol compound provided by this invention integrates multiple functions, including urease inhibition, nitrification inhibition, and plant growth promotion, achieving a comprehensive effect. Eugenol not only improves nitrogen fertilizer utilization and reduces nitrogen loss by regulating soil microbial activity, but also directly promotes the growth of the taproot of tobacco seedlings and increases the number of primary lateral roots. This makes it possible for eugenol to replace multiple synergists / stimulants in the development of novel green nitrogen fertilizer products, reducing energy consumption and costs.

Description

Technical Field

[0001] This invention belongs to the field of plant root growth regulation technology, specifically relating to the application of syringic acid, a biological nitrification inhibitor, in promoting tobacco root growth. Background Technology

[0002] Recent studies have found that bionitrification inhibitors can directly regulate physiological processes within plants to suppress root growth. For example, methylparaben (MHPP), a sorghum-derived bionitrification inhibitor, significantly inhibited root growth in the model plant Arabidopsis thaliana and the medicinal plant Perilla frutescens. MHPP mainly affects the sensing and response of auxin in the root tip by inducing nitric oxide accumulation and increasing reactive oxygen species levels, thus inhibiting cell division in the root tip meristem and taproot growth. Another bionitrification inhibitor secreted by sorghum, sorgoleone, can inhibit photosynthesis within the plant. These direct negative regulation effects on plant growth will affect the future development and application of bionitrification inhibitors, limiting their practical application.

[0003] Syringic acid, a biological nitrification inhibitor discovered in rice root exudates, can inhibit nitrogen nitrification at low concentrations and simultaneously delay urea hydrolysis, reducing nitrogen loss and N2O emissions. However, previous research has primarily focused on its application in regulating soil nitrogen transformation and microbial activity; its application in regulating root growth of my country's main tobacco varieties remains undisclosed. In flue-cured tobacco production, screening for plant-derived functional substances that simultaneously reduce nitrogen loss and directly benefit plant growth will drive the development of new, efficient, green nitrogen fertilizers and tobacco seedling growth regulators, holding significant practical importance for improving the quality and efficiency of flue-cured tobacco production. Summary of the Invention

[0004] Technical Problem Solved: This invention addresses the aforementioned technical problem by providing an application of syringic acid in regulating plant root growth. Syringic acid integrates multiple functions, including urease inhibition, nitrification inhibition, and plant growth regulation, achieving a comprehensive effect. This provides a simple and effective solution for improving nitrogen fertilizer utilization and reducing nitrogen loss in agricultural production, while simultaneously promoting crop root growth and stress resistance.

[0005] Technical solution: Application of eugenol in promoting plant root growth.

[0006] The indicators for judging root growth mentioned above are the length of the plant's taproot and the number of lateral roots.

[0007] Preferably, the concentration of eugenol added is 10~100 μM.

[0008] The plant mentioned above is tobacco.

[0009] Application of eugenolic acid in the preparation of tobacco seedling growth regulator products.

[0010] Beneficial Effects: This invention provides the multi-directional regulatory effect of eugenol, which not only improves nitrogen fertilizer utilization and reduces nitrogen loss by regulating soil microbial activity, but also directly promotes the growth of the taproot and the number of lateral roots at appropriate concentrations. This further broadens the application field of eugenol and enhances its industrial application value. Eugenol possesses single-molecule multifunctionality, acting as a combined agent for multiple fertilizer synergists and stimulants. In the preparation of new nitrogen fertilizers or stimulants in agricultural production, it can replace the addition of multiple synergists / stimulants, reducing the types of synergists / stimulants, lowering energy consumption and costs, and mitigating the potential environmental threats posed by multiple synergists / stimulants. Eugenol can directly promote root growth and can be sprayed onto plants as a synergist or stimulant, rather than being applied to the soil like other nitrogen synergists, thus saving labor. Attached Figure Description

[0011] Figure 1 The effects of different amounts of syringic acid on the growth of the taproot (a) and the number of lateral roots (b) of K326 tobacco seedlings.

[0012] Figure 2 The effects of different amounts of eugenol added on the growth of the taproot (a) and the number of lateral roots (b) of Yunyan 85 tobacco seedlings. Detailed Implementation

[0013] Test plants: The plant material was the tobacco variety K326.

[0014] Test reagent: Syringic acid (C9H) 10 O5).

[0015] Experimental treatment: Six final concentrations of syringic acid were set for the experiment: 0 μM, 10 μM, 25 μM, 50 μM, 100 μM, and 200 μM.

[0016] Experimental steps:

[0017] Tobacco seeds were placed into sterilized 1.5 mL centrifuge tubes, along with 1 mL of 10% H₂O₂ and 10 μL of sodium dodecyl sulfate. The tubes were vortexed until thoroughly sterilized, and the mixture was kept for 15 min. The centrifuge tubes were then sprayed with 75% alcohol for further sterilization before being transferred to a clean bench. The seeds were rinsed 5-7 times with sterile water using a pipette until clean. A suitable amount of 0.1% agarose solution was then added to suspend the seeds. The seeds were sown onto a standard MS germination culture substrate (Sigma-Aldrich, pH adjusted to 5.80). The substrate plate was sealed with Parafilm and placed vertically in a light-treated culture chamber, allowing the roots to grow vertically downwards along the substrate surface. The photoperiod in the culture chamber was 16 h / 8 h, the temperature was (23±1) ℃, and the light intensity was 100 μmol·m⁻²·s⁻¹. After germinating tobacco seeds on conventional culture medium for 7 days, uniformly growing tobacco seedlings were transferred to substrates treated with different concentrations for continued growth. On day 5 of culture, the taproot length and lateral root number were measured, with 15 replicates for each treatment. Taproot elongation: Initial root length was marked at the bottom of the substrate after transplanting, and the net growth over 5 days was measured with a ruler on day 5. Taproot elongation refers to the additional length of the taproot after transfer to the treatment plate.

[0018] 1.5 Experimental Results

[0019] Compared with the control group without added syringic acid, treatments with 25 μM, 50 μM, and 100 μM syringic acid significantly promoted the growth of the K326 taproot by 11%–23%, with the 50 μM treatment showing the best promoting effect, while 10 μM syringic acid had no significant promoting effect. Figure 1 a). The promoting effect gradually decreases with increasing concentration, and at 200 μM, it slightly inhibits the growth of the primary root.

[0020] Compared with the control group without added syringic acid, treatments with 10 μM, 25 μM, 50 μM, and 100 μM syringic acid significantly promoted the number of primary lateral roots in tobacco K326 by approximately 20%–68%, with the 25 μM treatment showing the best promoting effect on the number of lateral roots. Figure 1 (b) The promoting effect gradually decreased with increasing concentration, and the 200 μM treatment had no significant effect on lateral root growth. Combined with the results on the taproot, the 25–50 μM syringic acid addition had the best promoting effect on the taproot and lateral roots of K326 seedlings.

[0021] Experimental Design

[0022] Test plants: The plant material was the tobacco variety Yunyan 85.

[0023] Experimental procedure: The reagents, experimental treatment and experimental procedure are the same as in Example 1.

[0024] 2.2 Experimental Results

[0025] Compared with the control group without added syringic acid, treatments with 25 μM and 50 μM syringic acid significantly promoted the growth of the main root of Yunyan 85 by approximately 10%, while 10 μM syringic acid had no significant promoting effect. Figure 2 a). The promoting effect gradually decreased with increasing concentration, and it also slightly inhibited the growth of the primary root at 100 μM and 200 μM.

[0026] Compared with the control without added syringic acid, treatments with 10 μM, 25 μM, and 50 μM syringic acid significantly promoted approximately 40%–92% of the number of primary lateral roots in tobacco Yunyan 85. Figure 2 (b) Among the treatments, 25 μM showed the best promoting effect. The promoting effect gradually decreased with increasing concentration, and 100 μM and 200 μM treatments had no significant effect on lateral root growth. Combined with the results on the primary root, 25 μM syringic acid supplementation had the best promoting effect on both primary and lateral roots of Yunyan 85 seedlings.

Claims

1. Application of 10~100 μM syringic acid in promoting the length of the main root and the number of lateral roots in tobacco.

2. The application according to claim 1, characterized in that, The tobacco varieties mentioned are K326 and Yunyan 85.

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