Cotton leaf curl disease – an emerging threat to cotton production worldwide

Abstract

Cotton leaf curl disease (CLCuD) is a serious disease of cotton which has characteristic symptoms, the most unusual of which is the formation of leaf-like enations on the undersides of leaves. The disease is caused by whitefly-transmitted geminiviruses (family Geminiviridae, genus Begomovirus) in association with specific, symptom-modulating satellites (betasatellites) and an evolutionarily distinct group of satellite-like molecules known as alphasatellites. CLCuD occurs across Africa as well as in Pakistan and north-western India. Over the past 25 years, Pakistan and India have experienced two epidemics of the disease, the most recent of which involved a virus and satellite that are resistance breaking. Loss of this conventional host-plant resistance, which saved the cotton growers from ruin in the late 1990s, leaves farmers with only relatively poor host plant tolerance to counter the extensive losses the disease causes. There has always been the fear that CLCuD could spread from the relatively limited geographical range it encompasses at present to other cotton-growing areas of the world where, although the disease is not present, the environmental conditions are suitable for its establishment and the whitefly vector occurs. Unfortunately recent events have shown this fear to be well founded, with CLCuD making its first appearance in China. Here, we outline recent advances made in understanding the molecular biology of the components of the disease complex, their interactions with host plants, as well as efforts being made to control CLCuD.

Molecular and Biochemical Characterization of Cotton Epicuticular Wax in Defense Against Cotton Leaf Curl Disease

“…The results of virus symptoms appearance were in accordance with (16) and (17). The role of beta satellite Azmat Ullah Khan M. et al molecules.μL -1 of β-satellite was maximum in G. hirsutum, while it was not detectable in G. arboreum C: molecules.μL -1 of DNA-A was maximum in G. hirsutum, while it was not detectable in G. arboreum whereas the error bars represent the variation among 3 replicates is well-defined in suppressing the phyto-immune system that ultimately results in development of severe viral symptoms (18,19).…”

Identification and expression profiling of CLCuV-responsive transcripts in upland cotton (Gossypium hirsutum L.)

“…The disease occurs across Africa and southern Asia (Sattar et al, 2013). Cotton production has declined 11.3%, i.e.…”

Assessment of genetic diversity of cotton genotypes for various economic traits against cotton leaf curl disease (CLCuD)

“…The situation in southern Asia is more complex than in Africa: during the two CLCuD epidemics in Pakistan and India, at least six distinct begomovirus species have been identified in cotton (Kirthi et al, 2004;Sattar et al, 2013;Brown et al, 2015).…”

“…It was also recently reported in China. This disease is characterized by several whitefly transmitted begomoviruses (Family: Geminiviridae, Genus: Begomovirus) associated with specific satellite molecules (alpha-and betasatellites), which are responsible for symptom development (Sattar et al, 2013). The infected cotton plants (Gossypium L.) show a range of symptoms including vein thickening/ swelling, leaf enations (which develop into leaf-like structures in extreme cases), and cupshaped leaf curling.…”