United States of America, As Represented by the Secretary of Agriculture

Sanford Scientific, Inc.

Boyce Thompson Institute for Plant Research

Joyce Van Eck

John C Sanford

Alan D Blowers

Franzine Smith

Tau-San Chou

Robert B Eisenreich

Li Li

David F Garvin

The present invention relates to a nucleic acid construct having a nucleic acid molecule configured to silence &#x3b2;-carotene hydroxylase expression, and host cells, expression systems, plants, and plant seeds having the nucleic acid construct. The present invention also relates to a method of enhancing beta-carotene content by growing a transgenic plant from a plant or seed transformed with the construct.

Enhancement of beta-carotene content in plants

The cauliflower (L. var.) Or gene is a semi-dominant, single-locus mutation. It induces the accumulation of high levels of beta-carotene in various tissues that are normally devoid of carotenoids, turning them orange. Using a map-based cloning strategy, we identified a single gene representing Or and successfully verified its identity by functional complementation in the wild type cauliflower. The Or gene encodes a plastid membrane protein containing the DnaJ zinc figure domain. A likely gain-of-function mutation from a 4.3-kb retrotransposon insertion in the Or allele confers the orange phenotype in the mutant. Southern blot analysis revealed that Or is a single-copy sequence in the cauliflower genome. High level of expression of the Or gene and the protein was found in very young leaves, curds, and flowers at comparable abundance between wild type and the Or mutant. Or likely functions in regulating the differentiation of some non-photosynthetic plastids into chromoplasts, which provide the deposition 'sink' for carotenoid accumulation. Successful demonstration of Or in conferring carotenoid accumulation in potato tubers indicates its potential use to improve the nutritional value in staple crops.

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Since its introduction into North America over 170 years ago, the poinsettia has become a major ornamental potted plant, and is an important component of the U.S. floral industry. Susceptibility to insect pests and diseases caused by pathogens remains a problem for poinsettia production, even under greenhouse conditions. While chemical treatment can control certain insect pests and disease pathogens, such treatment can also have an adverse effect upon poinsettias. The methods described herein provide a means to genetically engineer transgenic poinsettia that express macromolecules capable of protecting the plant against the insects and pathogens. The production of transgenic plants can also be used to enhance the commercial value of poinsettia by controlling characteristics such as flower color.

Production of transgenic poinsettia

The invention provides antimicrobial peptides, nucleic acid constructs encoding them, methods for transforming plant cells, and transgenic plant tissue that expresses the antimicrobial peptide genes and thereby exhibit improved resistance to plant pathogens.

Growing community of inventors

Ithaca, NY, United States of America

Joyce Van Eck