IP Verse

Gene Conferring Resistance To Cercospora Beticola In Beets

Patent No. US11597944 (titled "Gene Conferring Resistance To Cercospora Beticola In Beets") was filed by Kws Saat Se & Co Kgaa on Aug 28, 2020.

What is this patent about?

’944 is related to the field of plant breeding, specifically addressing the problem of Cercospora leaf spot disease in plants of the *Beta vulgaris* species, including sugar beets, beetroot, and chard. This disease, caused by the fungus *Cercospora beticola*, leads to significant crop losses and necessitates the use of costly and environmentally damaging fungicides. Existing Cercospora-tolerant cultivars rely on multiple resistance genes with small effects, resulting in laborious breeding processes and reduced yield performance.

The underlying idea behind ’944 is the identification and isolation of a single dominant gene from *Beta vulgaris* subsp. *maritima* that confers a strong resistance to *Cercospora beticola*. This gene encodes a polypeptide that, when expressed in a plant, provides a substantial resistance effect, simplifying breeding efforts and potentially eliminating the need for multiple resistance genes.

The claims of ’944 focus on a *Beta vulgaris* subsp. *vulgaris* plant comprising a nucleic acid molecule encoding a polypeptide that confers resistance to *Cercospora beticola*. The nucleic acid molecule must encode a polypeptide with at least 95% amino acid sequence identity to SEQ ID NO: 3. The claims also cover a method of producing a *Beta* plant with improved resistance by introgressing a chromosomal interval containing the resistance-conferring gene, mapped between specific markers, into the plant.

The invention works by introducing the identified resistance gene into a plant's genome, either through traditional breeding techniques or genetic engineering. The expressed polypeptide then confers resistance to *Cercospora beticola*. The dominant nature of the gene means that even a single copy in the plant's genome provides a significant level of protection. This contrasts with previous approaches that relied on multiple genes with smaller individual effects, which were more difficult to breed for and often associated with undesirable traits.

’944 differentiates itself from prior solutions by providing a single, easily transferable gene that confers a strong resistance to *Cercospora beticola*. This simplifies the breeding process, reduces the risk of introducing unwanted traits (linkage drag), and allows for the rapid development of high-yielding, resistant cultivars. The invention also provides methods for identifying plants carrying this resistance gene, facilitating marker-assisted selection in breeding programs.

How does this patent fit in bigger picture?

Technical landscape at the time

In the late 2010s when ’944 was filed, plant breeding at a time when introducing new traits into crops was typically implemented using traditional crossing or genetic modification techniques. When identifying desirable genes commonly relied on extensive field trials and phenotypic selection rather than precise molecular markers. When introducing disease resistance relied on quantitative trait loci (QTL) mapping, which was often complex and time-consuming.

Novelty and Inventive Step

The examiner allowed the application after amendments to the claims and the filing of a terminal disclaimer. The amendments addressed previous rejections related to written description issues stemming from hybridization language and double patenting. The examiner had offered amendments to remove the problematic hybridization language. After these changes, all claims were considered allowable.

Claims

This patent contains 22 claims, with independent claims 1 and 22. Independent claim 1 focuses on a Beta vulgaris plant with a specific nucleic acid molecule conferring resistance to Cercospora beticola, while independent claim 22 focuses on a method of producing a sugar beet plant with improved resistance to Cercospora beticola by introgressing a specific chromosomal interval. The dependent claims generally elaborate on and refine the characteristics and methods related to the plant and its resistance to Cercospora beticola, as defined in the independent claims.

Key Claim Terms New

Definitions of key terms used in the patent claims.

Term (Source)Support for SpecificationInterpretation
Amino acid sequence according to SEQ ID NO: 3
(Claim 1, Claim 22)		“Analyses yielded that the LRR gene has a moderate protein homology to the Cf-2 resistance protein from the tomato (UNIPROT|Q41397_SOLPI P. Cf-2.1) (sequence identity =38%). In fact, the identified Cercospora resistance-conferring protein is the best sugar beet protein homolog to the Cf-2 tomato resistance protein.”The specific amino acid sequence identified as SEQ ID NO: 3 in the sequence listing of the patent application.
Beta vulgaris subsp. vulgaris
(Claim 1)		“A “plant of the genus Beta” belongs to the amaranth family (Amaranthaceae). Numbering among these plants are plants of the species Beta macrocarpa, Beta vulgaris, Beta lomatogona, Beta macrorhiza, Beta corolliflora, Beta trigyna, and Beta nana. A plant of the species Beta vulgaris is, in particular, a plant of the subspecies Beta vulgaris subsp. vulgaris.”A subspecies of Beta vulgaris, which includes sugar beet, chard, and beetroot.
Cercospora beticola
(Claim 1, Claim 22)		“Cercospora leaf spot is one of the most important, globally prevalent leaf diseases of plants from the species Beta vulgaris and Spinacia oleracea. It is caused by the fungus Cercospora beticola. Plants infested by this disease typically form small, relatively round leaf spots (2-3 mm) that are light gray in the middle and are surrounded by a red-brown border.”A fungus that causes Cercospora leaf spot disease in plants, particularly in Beta vulgaris.
Chromosomal interval
(Claim 22)		“With the aid of the setup of a population of over 4,000 dividing descendants and the development of special recombination screens, the target region was reduced, and thus ever further isolated, via analysis of informative recombinants (genotypical and phenotypical) in a series of resistance tests. This genetic mapping, as well as the creation of physical maps accompanied by WHG sequencing (“whole genome sequencing”), comparative BAC (Bac-by-Bac) sequencing, and bioinformatic analyses, led to the identification of three recombinant genotypes that confirmed the resistance gene (1 recombinant in the neighboring gene, on the one hand, and 2 recombinants in the neighboring gene, on the other).”A region of a chromosome that contains genetic markers associated with resistance to Cercospora beticola.
Nucleotide sequence encoding a polypeptide
(Claim 1, Claim 22)		“The present invention relates to a nucleic acid molecule that is able to confer a resistance to Cercospora—in particular, to the fungus Cercospora beticola—in a plant, and, in particular, in Beta vulgaris subsp. vulgaris. The polypeptide which is encoded by the nucleic acid molecule is thereby produced in the plant.”A sequence of nucleotides that, when translated, produces a polypeptide.

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US11597944

KWS SAAT SE & CO KGAA
Application Number
US17005903
Filing Date
Aug 28, 2020
Status
Granted
Expiry Date
Mar 12, 2039
External Links
Slate, USPTO, Google Patents