An Emulsion-Based Formulation for Increasing the Resistance of Plants to Salinity Stress: US20160302416A1 Patent Evaluation ^†

Abstract

This study describes the use of an emulsion-based formulation to increase the resistance of plants to salinity and other abiotic stress. Inventors have described and claimed, through the US20160302416A1 patent, an emulsion-based formulation for increasing the resistance of a plant to damage caused by one or more abiotic stresses. The earliest priority date of the US20160302416A1 patent was 6 December 2013, with five patent families and four filled jurisdictions. Based on patent classification, the invention covered by the patent concerns the preservation of plants or parts thereof (e.g., inhibiting evaporation, improving the appearance of leaves, etc.). To prove the concept of this invention, studies were initiated in the greenhouse to look at the impact of different formulations on spring wheat and turf grass grown under salt stress conditions. The inventors confirmed that the proposed formulations could increase the tolerance of spring wheat and turf grass to the presence of excess salt. The method of applying the emulsion-based formulation to the spring wheat or to the turf grass at the onset of the salt stress conditions enhanced the tolerance to the stress conditions.

1. Introduction

The protection of plants from environmental stresses is one of the major concerns in the field of agriculture. Growing plants are subjected to a variety of environmental stresses of non-biological origins, referred to as abiotic stresses, including cold, water logging, transplant shock, low light, drought, salinity, etc. [1,2]. In agriculture, conventional plant treatments are generally unable to provide plants with resistance to abiotic stresses and are therefore limited to providing benefits to otherwise healthy or flourishing plants. However, commercial agronomical processes require additional plant treatments to reduce plant stress or enhance the plant’s ability to resist common abiotic stresses and/or to recover quickly from such stresses. A typical example of common abiotic stress in marginal lands and sea basins includes continuous exposure to saline water which causes soil salinity. Salinity stress results in poor or no yields mainly due to reducing root growth as well as reducing the nutritional status of plants and/or fruits. More specifically, salinity directly affects the morphology, physiology, and metabolism of plants [3,4].

When a plant is exposed to abiotic stress, it develops certain natural defense mechanisms against such stress, but there is a need to provide plants with enhanced abilities to overcome such stress. Salinity causes two major effects in the plant, i.e., ion toxicity and osmotic stress [5].

This study describes the state of the art by introducing what has been patented in relation to formulations for increasing the resistance of plants to abiotic stresses, among others, salinity stress, and describes the patent US20160302416A1. Regarding preparation methods and applications, this study, in the form of a patent evaluation, describes the use of combinations, including an emulsion-based formulation with a pigment, to increase the resistance of plants to salinity stress. Furthermore, to prove the concept of this invention, studies were initiated in the greenhouse to look at the impact of different formulations on spring wheat and turf grass grown under salt stress conditions.

2. Patent Analysis

The studied patent (US20160302416A1) was invented by Fefer Michael and Liu Jun from Canada, and it was filed by the company Suncor Energy Inc. (Calgary, AB, Canada). The earliest priority date of this patent was 6 December 2013, with five patent families. A patent family is a collection of published patent documents relating to the same invention as the initial document (i.e., a priority document), or to several inventions sharing a common aspect that are published at different times in the same country or published in different countries or regions. That means a number of different patent documents whose technical content is considered identical [6]. The jurisdictions of the related five filled patents correspond to Canada [7,8], the United States [9], Uruguay [10], and the global system for filing patent applications [11], known as the Patent Cooperation Treaty (PCT), and administered by the World Intellectual Property Organization (WIPO) [12].

The International Patent Classification (IPC) is a hierarchical system in the form of codes, which divides all technological areas into a range of sections, classes, subclasses, groups, and subgroups. It is an international classification system that provides standard information to categorize inventions and evaluate their technological uniqueness [13]. Concerning these patents, the IPC codes are presented in

Table 1. Classifications of the five patent families of this study [7,8,9,10,11].

IPC Codes	Description
A01N3/00	Preservation of plants or parts thereof (e.g., inhibiting evaporation, improving the appearance of leaves, etc.).
A01N27/00	Biocides, pest repellants or attractants, or plant growth regulators containing hydrocarbons.
A01N43/90	Biocides, pest repellants or attractants, or plant growth regulators containing heterocyclic compounds.
A01N61/02	Biocides, pest repellants or attractants, or plant growth regulators containing substances characterized only by the mode of action, such as mineral oils, and tar oils and tar distillates.

.

3. Patent Evaluation: Materials, Methods, and Results

Inventors described and claimed through these patents a method and an emulsion-based formulation for increasing the resistance of a plant to damage caused by one or more abiotic stresses, among others, salinity stress, which comprises applying an emulsion amount to the plant. The claimed emulsion-based formulation comprises paraffinic oil, emulsifier, pigment, water, and additives. A typical effective agricultural combination of these oil-in-water emulsions is presented in

Table 2. Detail of the proposed emulsion-based formulation through the studied patent [9].

Emulsion Components	Description
Paraffinic oil	The paraffinic oil can include a paraffin having an average number of carbon atoms of 23. Paraffinic oil with 98% paraffin content: isoparaffin.
Emulsifier	Emulsifiers include natural or synthetic surfactant or alcohol. Silicone surfactant; Silicone polyether; Polyethylene glycol.
Pigment	The pigment is a water-based pigment dispersion (i.e., hydrophilic) or an oil-based pigment dispersion (i.e., hydrophobic). Copper phthalocyanine: 40% polychlorinated Cu(II) phthalocyanine.
Water	The oil-in-water emulsions include water. Distilled water and/or other waters having a low mineral electrolyte content.
Additives	The formulation can further include a combination of additives. Anti-settling agents; Plant growth regulators; Conventional chemical fungicides.

.

Two studies concerning salt stress were carried out to prove the concept of this invention, and three oil-in-water emulsion compositions were tested:

• Composition A: Paraffinic oil, having a composition of 98% isoparaffin.
• Composition B: 40% polychlorinated Cu(II) phthalocyanine dispersed in water.
• Composition C: A combination of paraffinic oil and polychlorinated Cu(II) phthalocyanine dispersed in water in a ratio of 30:1, having 90% isoparaffin and 2.4% polychlorinated CU(II) phthalocyanine.

Studies were initiated in the greenhouse to look at the impact of the three above-cited compositions on spring wheat and turf grass grown under salt stress conditions. It should be noted that all results obtained are included in the US20160302416A1 patent [9].

3.1. Spring Wheat

The first salt stress study was conducted on spring wheat in the greenhouse. Wheat seeds were grown in the greenhouse under full light for two to three weeks to reach the three-leaf stage. The wheat plants were treated with the compositions A and B by foliar application with a total spray volume of 935.40 L/ha. Salt stress was introduced 24 h later by drenching of a 150 ppm NaCl solution into each pot (500 mL/pot). A second salt solution was applied one week later. The treatments were performed on different samples under the conditions presented in

Table 3. Conditions of different plants’ treatment under salt stress: the case of spring wheat [9].

Condition 1	Salt Treatment (ppm) 2	Composition A (%)	Composition B (%)
1	150	0	0
2	150	5	0.312
3	150	5	0.625
4	150	5	1.25
5	0	0	0

¹ Condition: (1) Untreated control under salt stress; (2,3,4) Plants were treated with the compositions A and B by foliar application with a total spray volume of 935.40 L/ha; (5) Untreated control without salt stress. ² Salt treatment: NaCl solution into each pot.

. The plant continued to grow for two additional weeks, and the plant height and biomass data (fresh and dry weight) were then measured.

As results for this first salt stress study, each treatment showed no significant difference in plant height. However, the measured biomass (above ground) for each treatment by fresh weight and dry weight showed significant differences. The plants treated with the compositions A and B exhibited higher dry weight and fresh weight compared with the untreated control under salt stress. The treated plant under salt stress also exhibited similar biomass as an untreated control which was not subjected to salt stress.

3.2. Turf Grasses

The second salt stress study was conducted on turf grass grown in the greenhouse. Turf grass seed was sown in potting soil in the greenhouse under full light approximately four weeks before the trial start date. Upon trial initiation, pots were watered with different NaCl concentrations at a rate of 100 mL/pot, with additional applications occurring 1–2 times weekly thereafter. Half of the pots from each salt concentration were also treated with either a foliar application of water or the equivalent of 5.2 g/m² of the composition C at a rate of 935.40 L/ha, with applications repeated every 14 days. Turf quality ratings (NTEP scale 1–9, where 6 = minimally acceptable turf, and 9 = excellent turf quality) were used to assess the effect of salt stress on overall turf health starting at trial initiation, and then repeated every two weeks thereafter (

Table 4. Conditions of different plants’ treatment under salt stress: the case of turf grass [9].

Salt Treatment (M) 1	Turf Quality (NTEP Scale 1–9)
	35 Days after Initial Treatment		49 Days after Initial Treatment
	Water 2	Composition C 3	Water 2	Composition C 3
0 (water)	7.3	8.8	6	9
0.03	6.3	8	5	8.3
0.06	5	7.5	3.5	7.8
0.09	4.8	6.8	3	7.8
0.12	5.8	6.3	5	5.3

¹ Salt treatment: NaCl solutions were watered into each pot at a rate of 100 mL/pot, 1–2 times weekly. ² Water: Plants were treated with water at a rate of 935.40 L/ha. ³ Composition C: Plants were treated with the equivalent to 5.2 g/m² of the composition C at a rate of 935.40 L/ha.

).

As results for this second salt stress study, turf grass showed no significant sign of stress during the first two applications (0 and 0.03 M) and no significant difference between the treatments. Turf quality ratings shown in Table 4 highlight results assessed 35 days after initial foliar applications (seven days after 3rd application) or 49 days after initial foliar applications (seven days after 4th application), as these were the dates when the greatest differences were observed between the composition C treated and water treated plants.

4. Conclusions

Soil salinity stress causes osmotic stress and affects the agronomical, physiological, and nutritional status of the plants. The studied patent (US20160302416A1) uses an emulsion-based formulation to increase the resistance of plants against salinity stress. Through this patent, the inventors claimed preparation methods/processes and applications of oil-in-water emulsions to treat plants under salt stress. The inventors confirmed that the proposed formulations could increase the tolerance of spring wheat and turf grass against salinity. According to the inventors, the method of applying the emulsion-based formulation to the spring wheat or to the turf grass at the onset of the salt stress conditions enhanced the tolerance to the stress conditions by improving the yield and quality of plants as compared to untreated plants subjected to the same salt stress. In particular, the quality of spring wheat and turf grass was not degraded as quickly or to the same extent as the control. Finally, the inventors proposed that the emulsion-based formulation could be applied prior to or during the crop growing period to improve salinity stress.