the new zealand institute for plant & food …...a novel pai encodes coronafacic acid in nzec1...
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The New Zealand Institute for Plant & Food Research Limited
Acquisition of a Pathogenicity Island encoding CFA by Pectobacterium carotovorum subsp. carotovorum causing blackleg
Andrew Pitman
The New Zealand Institute for Plant & Food Research Limited
Pectobacterium on potato
Dickeya sp. andPectobacterium sp. cause soft rotting of potato tubers
Pectobacterium atrosepticum (Pba) causes blackleg of potato stems
The New Zealand Institute for Plant & Food Research Limited
Coronafacic acid (CFA) encodes virulence on potato stems in Pba
The CFA cluster is encoded on a putative Horizontally Acquired Island (HAI2)
The New Zealand Institute for Plant & Food Research Limited
Some Pectobacterium carotovorum strains also cause blackleg on potato
Pcc NZEC1 Pcc ICMP5702cfa6 and cfa7 detected by PCR in NZEC1
The New Zealand Institute for Plant & Food Research Limited
Research Questions
1. Does CFA production enable Pectobacterium carotovorum strains to cause blackleg too?
2. How were the CFA genes acquired by Pectobacterium carotovorum NZEC1?
3. Are any other factors involved in blackleg?
The New Zealand Institute for Plant & Food Research Limited
1. NZEC1 (Pcc)2. PC1 (Pcc)3. ICMP1526 (Pba) 4. SCRI1043 (Pba)
The New Zealand Institute for Plant & Food Research Limited
CFA cluster in NZEC1
95% nucleotide identity to SCRI1043 CFA cluster
The New Zealand Institute for Plant & Food Research Limited
A novel PAI encodes coronafacic acid in NZEC1
• NZEC1HAI1• 98,502 bp• Delineated by 48 bp direct repeats that mediate HGT
NZEC1 (Pcc)
SCRI1043 (Pba)
ICMP1526 (Pba)
The New Zealand Institute for Plant & Food Research Limited
Conclusions
A highly conserved CFA biosynthetic cluster is present in both Pectobacterium carotovorum and Pectobacterium
atrosepticum that cause blackleg.
1. Does CFA production enable Pectobacterium carotovorum strains to cause blackleg too?
The New Zealand Institute for Plant & Food Research Limited
Conclusions
The CFA cluster is present on a unique PAI in PccNZEC1 suggesting independent evolution of Pectobacterium species to cause blackleg.
2. How were the CFA genes acquired by Pectobacterium carotovorum NZEC1?
The New Zealand Institute for Plant & Food Research Limited
Conclusions
Other factors such as the phytotoxin syringomycin may be required for development of blackleg.
3. Are any other factors involved in blackleg?
The New Zealand Institute for Plant & Food Research Limited
The New Zealand Institute for Plant & Food Research Limited
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