Methods of controlling reproduction in plants

Abstract

Methods are described herein for producing hybrid seed using male-sterile plants wherein reproductive function is restored by treatment of mutant plants with selected plant hormones. Plants comprising mutations in the allene oxide synthase gene are functionally male-sterile and are useful for the production of hybrid seed, wherein fertility is restored in the plants by treatment with jasmonic acid. Hybrid seed production is simplified and improved by this invention. The present invention also includes plants comprising mutations in genes affecting allene oxide synthase and / or hydroperoxide lyase.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] The present application claims the benefit of priority under 35 U.S.C. § 120 as a continuation of U.S. Ser. No. 10 / 322,924, filed Dec. 18, 2002, which claims the benefit of U.S. Ser. No. 60 / 342,264 filed Dec. 18, 2001, and U.S. Ser. No. 60 / 344,061, filed Dec. 26, 2001, which applications are incorporated by reference in their entireties for all purposes.TECHNICAL FIELD [0002] The present invention relates to novel methods of regulating plant phenotypes, in particular male sterility. The invention relates to methods of controlling reproduction in plants by, for example, affecting expression of allene oxide synthase (AOS) and / or hydroperoxide lyase (HPL). The invention further relates to affecting other plant phenotypes, such as expression of defense-related genes and pathogen resistance. BACKGROUND [0003] Production of hybrid seed for commercial sale is a large industry. Hybrid plants grown from hybrid seed, benefit from the heterotic ef...

AI Technical Summary

Problems solved by technology

Simple mechanical methods for hybrid seed production typically can only be used if the selected plant species has spatially separate male and female flowers or if the species has separate male and female plants.

Accordingly, emasculation of these crop plants is not a simple procedure.

It is possible to hand remove the pollen forming organs before pollen is shed, however, this is a labor intensive and expensive form of hybrid seed production.

Commercial production of hybrid seed using gametocides is limited by (i) the expense and availability of the chemicals, and (ii) the reliability and length of action of the applications.

When plants have extended flowering periods, gametocides are typically not effective because new flowers are produced that are not affected by previous treatment.

Repeated application of chemicals is impractical primarily because cost becomes prohibitive.

In such methods, plants that are used as females (i) fail to make pollen, (ii) fail to shed pollen, or (iii) produce pollen biochemically unable to provide self-fertilization.

Numerous difficulties are associated with the use of self-incompatibilities, including, propagation and availability of the self-incompatible female line, and stability of the self-incompatibility.

Self-incompatible systems that can be deactivated are often vulnerable to stressful climatic conditions, where such environmental stresses reduce the effectiveness of the biochemical self-pollination block.

Commercial utility of nuclear sterility systems is limited by the expense of clonal propagation and roguing the female rows of self-fertile plants.

For example, a specific mutation in the mitochondria can, when in a selected nuclear background, lead to the failure of mature pollen formation.

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