Enhanced resistance to bacterial and fungal pathogens by overexpression of a human cathelicidin antimicrobial peptide (hCAP18/LL-37) in Chinese cabbage

Abstract

The human cathelicidin antimicrobial protein hCAP18, which includes the C-terminal peptide LL-37, is a multifunctional protein. As a possible approach to enhancing the resistance to plant disease, a DNA fragment coding for hCAP18/LL-37 was fused at the C-terminal end of the leader sequence of endopolygalacturonase-inhibiting protein under the control of the cauliflower mosaic virus 35S promoter region. The construct was then introduced into Brassica rapa. LL-37 expression was confirmed in transgenic plants by reverse transcription-polymerase chain reaction and western blot analysis. Transgenic plants exhibited varying levels of resistance to bacterial and fungal pathogens. The average size of disease lesions in the transgenic plants was reduced to less than half of that in wild-type plants. Our results suggest that the antimicrobial LL-37 peptide is involved in wide-spectrum resistance to bacterial and fungal pathogen infection.

Transcriptional Profiling of Soft-rot Resistant Transgenic Chinese Cabbage (Brassica rapa L.) Constitutively Overexpressing a Human Cathelicidin Antimicrobial Peptide (hCAP18/LL-37)

“…Some research has been performed to bolster plant defenses against bacteria and fungi by genetically engineering plants to express antimicrobial peptides Prasad et al 2008). Previously, we developed homozygous Chinese cabbage lines stably expressing LL-37, which did not cause adverse effects on the plant phenotypes (Jung et al 2012). LL-37 peptide was properly targeted to the extracellular space even with a foreign plant signal peptide.…”

“…In our previous study, we produced transgenic Chinese cabbage plants with less susceptibility to soft rot via constitutively overexpressing a human cathelicidin antimicrobial peptide (hCAP18/LL-37) (Jung et al 2012). To reveal the molecular mechanisms underlying soft rot resistance in transgenic lines, the global transcriptional profile of transgenic lines (TG23, TG34) and WT were compared by Chinese cabbage genome GeneChip analysis.…”

“…A large number of antimicrobial peptides from different organisms have been characterized (Simmaco et al 1998). In our previous study, we produced transgenic Chinese cabbage plants with less susceptibility to soft rot via constitutively overexpressing a human cathelicidin antimicrobial peptide (hCAP18/LL-37) (Jung et al 2012). The human cathelicidin antimicrobial protein hCAP18 is the only member of the mammalian cathelicidin family of proteins that is present in humans (Gudmundsson et al 1996).…”

Application of Antimicrobial Peptides for Disease Control in Plants

“…Disease lesions: 0, no lesion; 1, lesion size 0.1-0.5 cm; 2, 0.5-1.5 cm; 3, 1.5-3.5 cm; 4, 3.5-5.5 cm; 5, 5.5-8.5 cm; and 6, over 8.5 cm or plant dead. (Jung et al 2012).…”

“…They are a first line of defense in plants and animals, and resistance against them is much less observed compared with current antibiotics (Hancock 1997). AMPs from various sources have been demonstrated to confer resistance against fungal and bacterial pathogens in an array of genetically engineered plant species, including Arabidopsis (Maloy 1995), tobacco (Ramamoorthy et al 2006;Kang et al 2009;, Chinese cabbage (Jung et al 2012), rice (Gordon et al 2005;Oyston et al 2009), tomato (Lupetti et al 2000), cotton (Lupetti et al 2003), potato (Brouwer et al 2011), pear (Hwang et al 1998), banana (Ramamoorthy et al 2006) and hybrid poplar (Nguyen et al 2005).…”