Antisense Suppression of a (+)-δ-Cadinene Synthase Gene in Cotton Prevents the Induction of This Defense Response Gene during Bacterial Blight Infection But Not Its Constitutive Expression  

Abstract

In cotton (Gossypium hirsutum) the enzyme (1)-d-cadinene synthase (CDNS) catalyzes the first committed step in the biosynthesis of cadinane-type sesquiterpenes, such as gossypol, that provide constitutive and inducible protection against pests and diseases. A cotton cDNA clone encoding CDNS (cdn1-C4) was isolated from developing embryos and functionally characterized. Southern analysis showed that CDNS genes belong to a large multigene family, of which five genomic clones were studied, including three pseudogenes and one gene that may represent another subfamily of CDNS. CDNS expression was shown to be induced in cotton infected with either the bacterial blight or verticillium wilt pathogens. Constructs for the constitutive or seed-specific antisense suppression of cdn1-C4 were introduced into cotton by Agrobacterium-mediated transformation. Gossypol levels were not reduced in the seeds of transformants with either construct, nor was the induction of CDNS expression affected in stems of the constitutive antisense plants infected with Verticillium dahliae Kleb. However, the induction of CDNS mRNA and protein in response to bacterial blight infection of cotyledons was completely blocked in the constitutive antisense plants. These results suggest that cdn1-C4 may be involved specifically in the bacterial blight response and that the CDNS multigene family comprises a complex set of genes differing in their temporal and spatial regulation and responsible for different branches of the cotton sesquiterpene pathway.

Volatile sesquiterpenes from fungi: what are they good for?

“…The resulting metabolites are modulated by other enzymes which are induced by environmental stress factors. Little is known about the specific mechanisms in fungi but from plants several environmental factors, including UV-radiation (Back et al 1998), infection (Townsend et al 2005) and herbivore attack (Yuan et al 2008), have been identified which lead to the enhanced production of volatile sesquiterpenes.…”

Proteomic and Virus-induced Gene Silencing (VIGS) Analyses Reveal That Gossypol, Brassinosteroids, and Jasmonic acid Contribute to the Resistance of Cotton to Verticillium dahliae

“…Gossypol is one of the most important sesquiterpene phytoalexin, which exists specifically in cotton and plays a crucial role in the defense against the invasion of pathogens and insects (20). Though many phytoalexin-related genes have been shown to be important in mediating cotton defense, the molecular mechanism is unknown (21,22). As sequencing technology develops, a number of genes related to disease resistance (e.g.…”

Molecular cloning and expression analysis of a new WD40 repeat protein gene in upland cotton

“…Most research has focused on the biosynthesis of gossypol and its important role in cotton growth, so that although cotton pigment glands have attracted the attention of researchers for a number of years, the molecular mechanism of their formation is unknown (Luo et al 2001;Townsend et al 2005;Xu et al 2004). Our group has been researching the molecular mechanism of cotton pigment gland formation.…”

“…Most cotton plants and seed contain pigment glands that produce gossypol, which is an important deterrent against a wide variety of pests and microbial pathogens Townsend et al 2005). Cotton could also become one of the largest sources of edible oilseed and also be a source of relatively high-quality protein (Sunilkumar et al 2006;Bertrand et al 2005;Gerasimidis et al 2007); however, cottonseed is an underutilised food or feed source due to the presence of gossypol, a terpenoid aldehyde that is toxic to non-ruminant animals and humans (Sang et al 1980;Shandilya et al 1982;Weinbauer et al 1983;Heywood 1988;Du et al 2004;Stipanovic et al 2006).…”