Composition and method for stress mitigation in plants

Abstract

A composition and method to mitigate plant autophagy and / or apoptosis of newly developing cells in plants grown under environmentally stressful growing conditions. Exogenous application of a cytokinin, preferably kinetin, to the foliage of plants has been discovered to overcome, or at least mitigate, autophagy when applied during or just prior to flowering. Several provided examples show that, in laboratory and field experiments, exogenous foliar application of cytokinin to the leaves and flowers of plants lessened cytokinin deficiencies in plant tissues grown in high temperatures, thereby mitigating autophagy and apoptosis and greatly enhancing seed / crop production. The application of low concentrations of potassium together with the cytokinin appears to provide a synergistic effect by amplifying the effect of the cytokinin to lessen autophagy and increase crop productivity.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]This invention relates generally to a method and composition for mitigating plant autophagy or the degradation of older plant cells to supply nutrients to deficient newly-forming plant cells, which can occur during development (e.g., flowering) of new plant cells under stressful conditions, such as high temperatures. Moreover, this invention relates to the enhanced development of seeds, and consequently, the increased yield of harvestable grains from plants, including crop plants, that experience environmentally stressful growing conditions during development and growth.[0003]2. Description of the Related Art[0004]Traditionally, mineral fertilizers have been predominately applied to growing crop plants. Difficulties arise, however, when external stresses impede successful plant development, especially of grain or seed crops. Physical stresses, such as those inflicted by environmental temperatures being either too low or...

AI Technical Summary

Benefits of technology

[0008]Provide a method and composition to enhance the productivity and growth of crop plants;

[0009]Provide a method and composition to enhance the productivity and growth of crop plants grown under harsh environmental stresses;

[0010]Provide a method and composition to enhance the productivity and growth of plants grown under high temperature conditions;

[0015]Exogenous application to the plant canopy (i.e. leaves and flowers) of the plant growth regulator / hormone cytokinin has been discovered to prevent such autophagy by inducing the necessary production of sufficient nutrients (i.e., sugars) for the growth of new plant cells (i.e., successful and complete seed development). It is thought that genes controlling for increased levels of photosynthates (i.e., plant sugar / energy producers) are triggered by exogenous application of cytokinin. Additionally, the application of low concentrations of potassium along with the cytokinin has been found to substantially increase the effect of the cytokinin. Such results are unexpected with such low potassium concentrations, because they differ from the physiological effects normally attributed to higher application rates of fertilizer-grade potassium. It is thought that the application of low concentrations of potassium act much like other signaling molecules (e.g., hormones) in stimulating transcription of particular genes, such as the genes that express cytokinin effects. The synergy from the application of low concentrations of potassium and cytokinin to growing plants may also be realized under lower stress growing conditions.

[0016]The disclosed composition and its method of application represents a practical approach to mitigating plant autophagy, and any ensuing apoptosis, that results from stressful plant growing conditions, such as high temperatures. The method preferably includes the application of a plant hormone, primarily a cytokinin, to the foliage and / or flowers of plants at or about the time of plant flowering (e.g., during meiosis and when pollen is about to enter dehiscence). This autophagy-inhibiting agent is preferably the cytokinin, kinetin, however, other forms of cytokinin may be used singularly or in combination, such as zeatin, various forms of zeatin, N6-benzyl adenine, N6-(delta-2-isopentyl) adenine, 1,3-diphenyl urea, thidiazuron, CPPU (forchlorfenuron) or other chemical formulations with cytokinin-like activity. Preferably, but optionally, a low concentration of potassium is also applied together with the plant hormone to enhance the effects of the plant hormone as previously described.

[0017]In a first step, the cytokinin plant hormone is readied for application to the plants to be treated. The cytokinin plant hormone is preferably applied to the plants as an aqueous solution. Therefore, readying the cytokinin plant hormone may include one or more of the following activities: diluting the cytokinin plant hormone in sufficient water to create the desired concentration of cytokinin in the applied mixture / composition, adding low concentrations of potassium to the cytokinin plant hormone mixture / composition to enhance the effects of the applied cytokinin, loading the cytokinin plant hormone with or without potassium (or an aqueous mixture thereof) into a sprayer or tank for subsequent application to the plants to be treated, calibrating the sprayer or dosing applicator to meter the desired amount of the cytokinin plant hormone mixture to the plants to be treated and transporting the cytokinin plant hormone with or without potassium (or an aqueous mixture thereof) to the location of the plants to be treated.

Problems solved by technology

When growing temperatures are too high, the development of flowers and subsequent embryos (seeds) is known to be compromised, with the concomitant result that productivity of crop grains or other types of agronomic harvest is impaired and crop yields are drastically decreased.

Under extreme growing conditions, such as high temperatures, plants experience an inability to produce the nutrients, such as sugars, necessary for conducting normal anabolic processes (i.e., flower and embryo / seed development).

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