Gossypol and related compounds are produced and accumulate in the aboveground parts of the cotton plant, independent of roots as the source.

Use of Ultra-low gossypol cottonseed event as a scion in a graft combination confirmed that roots are not a source of terpenoids in the aboveground parts of a cotton plant. Gossypol and related terpenoids, derived from the same basic biosynthetic pathway, are present in the numerous lysigenous glands in the aboveground parts of a cotton plant. Roots, with sparse presence of such glands, do produce significant amount of gossypol and a different set of terpenoids.

Genes regulating gland development in the cotton plant.

In seeds and other parts of cultivated, tetraploid cotton (Gossypium hirsutum L.), multicellular groups of cells lysigenously form dark glands containing toxic terpenoids such as gossypol that defend the plant against pests and pathogens. Using RNA-seq analysis of embryos from near-isogenic glanded (Gl Gl Gl Gl ) versus glandless (gl gl gl gl ) plants, we identified 33 genes that expressed exclusively or at higher levels in embryos just prior to gland formation in glanded plants.

Selective fertilization with phosphite allows unhindered growth of cotton plants expressing the gene while suppressing weeds.

Weeds, which have been the bane of agriculture since the beginning of civilization, are managed manually, mechanically, and, more recently, by chemicals. However, chemical control options are rapidly shrinking due to the recent rise in the number of herbicide-resistant weeds in crop fields, with few alternatives on the horizon. Therefore, there is an urgent need for alternative weed suppression systems to sustain crop productivity while reducing our dependence on herbicides and tillage.

ptxD gene in combination with phosphite serves as a highly effective selection system to generate transgenic cotton (Gossypium hirsutum L.).

This report demonstrates the usefulness of ptxD/phosphite as a selection system that not only provides a highly efficient and simple means to generate transgenic cotton plants, but also helps address many of the concerns related to the use of antibiotic and herbicide resistance genes in the production of transgenic crops. Two of the most popular dominant selectable marker systems for plant transformation are based on either antibiotic or herbicide resistance genes. Due to concerns regarding their safety and in order to stack multiple traits in a single plant, there is a need for alternative selectable marker genes.

CRISPR/Cas9-mediated targeted mutagenesis in upland cotton (Gossypium hirsutum L.).

The clustered, regularly interspaced, short palindromic repeats (CRISPR)/CRISPR associated (Cas)9 protein system has emerged as a simple and efficient tool for genome editing in eukaryotic cells. It has been shown to be functional in several crop species, yet there are no reports on the application of this or any other genome editing technologies in the cotton plant. Cotton is an important crop that is grown mainly for its fiber, but its seed also serves as a useful source of edible oil and feed protein.

Cotton (Gossypium hirsutum L.).

Cotton continues to be a crop of great economic importance in many developing and some developed countries. Cotton plants expressing the Bt gene to deter some of the major pests have been enthusiastically and widely accepted by the farmers in three of the major producing countries, i.e.

RNAi-mediated Ultra-low gossypol cottonseed trait: performance of transgenic lines under field conditions.

Cottonseed remains a low-value by-product of lint production mainly due to the presence of toxic gossypol that makes it unfit for monogastrics. Ultra-low gossypol cottonseed (ULGCS) lines were developed using RNAi knockdown of δ-cadinene synthase gene(s) in Gossypium hirsutum. The purpose of the current study was to assess the stability and specificity of the ULGCS trait and evaluate the agronomic performance of the transgenic lines.

Ultra-low gossypol cottonseed: generational stability of the seed-specific, RNAi-mediated phenotype and resumption of terpenoid profile following seed germination.

Cottonseed, containing 22.5% protein, remains an under-utilized and under-valued resource because of the presence of toxic gossypol. RNAi-knockdown of δ-cadinene synthase gene(s) was used to engineer plants that produced ultra-low gossypol cottonseed (ULGCS).

Resistance against various fungal pathogens and reniform nematode in transgenic cotton plants expressing Arabidopsis NPR1.

Cotton is an economically important crop worldwide that suffers severe losses due to a wide range of fungal/bacterial pathogens and nematodes. Given its susceptibility to various pathogens, it is important to obtain a broad-spectrum resistance in cotton. Resistance to several fungal and bacterial diseases has been obtained by overexpressing the Non-expressor of Pathogenesis-Related genes-1 (NPR1) in various plant species with apparently minimal or no pleiotropic effects.

Expression of anti-K99 scFv in transgenic rice tissues and its functional characterization.

As a first step towards manufacturing functional anti-K99 single chain variable antibody fragment (scFv) in a plant system to prevent colibacillosis in neonatal calves, we investigated the feasibility of producing these antibodies in rice plants. Two scFv constructs, with or without the endoplasmic reticulum (ER) targeting KDEL sequence, were introduced into rice for either ER-retention of the recombinant antibody or its secretion. In agreement with several other published reports, extremely low-levels of scFv were produced in rice plants transformed with the construct lacking the ER-targeting sequence.

A comprehensive study of the use of a homologous promoter in antisense cotton lines exhibiting a high seed oleic acid phenotype.

As opposed to first-generation biotechnology products, such as pest-resistant crops and herbicide-resistant crops, second-generation products often utilize plant-derived, homologous or heterologous genes and/or promoters. In this study, we evaluated the ability of a promoter from a gene encoding a major storage protein in cottonseed to drive an antisense sequence of the cotton FAD2 gene to down-regulate the activity of Delta-12 desaturase enzyme in cottonseeds. The oleic acid level in the transgenic cottonseeds approximately doubled from the wild-type level of 15%, with a concomitant decrease in the level of linoleic acid.

Engineering cottonseed for use in human nutrition by tissue-specific reduction of toxic gossypol.

Global cottonseed production can potentially provide the protein requirements for half a billion people per year; however, it is woefully underutilized because of the presence of toxic gossypol within seed glands. Therefore, elimination of gossypol from cottonseed has been a long-standing goal of geneticists. Attempts were made to meet this objective by developing so-called "glandless cotton" in the 1950s by conventional breeding techniques; however, the glandless varieties were commercially unviable because of the increased susceptibility of the plant to insect pests due to the systemic absence of glands that contain gossypol and other protective terpenoids.

Cotton (Gossypium hirsutum L.).

Considering the economic importance of cotton in many developing and developed countries, there is an urgent need to accelerate the application of biotechnological tools to address the problems associated with the production of this crop and to improve the quality of fiber and seed. This requires a simple yet robust gene delivery/transformant recovery system. A protocol for the production of transgenic cotton plants was refined in our laboratory.