TY - JOUR
T1 - Tissue-specific gene expression in maize seeds during colonization by Aspergillus flavus and Fusarium verticillioides
AU - Shu, Xiaomei
AU - Livingston, David P.
AU - Franks, Robert G.
AU - Boston, Rebecca S.
AU - Woloshuk, Charles P.
AU - Payne, Gary A.
N1 - Publisher Copyright:
© 2014 BSPP AND JOHN WILEY & SONS LTD.
Copyright:
Copyright 2015 Elsevier B.V., All rights reserved.
PY - 2015/9/1
Y1 - 2015/9/1
N2 - Aspergillus flavus and Fusarium verticillioides are fungal pathogens that colonize maize kernels and produce the harmful mycotoxins aflatoxin and fumonisin, respectively. Management practice based on potential host resistance to reduce contamination by these mycotoxins has proven difficult, resulting in the need for a better understanding of the infection process by these fungi and the response of maize seeds to infection. In this study, we followed the colonization of seeds by histological methods and the transcriptional changes of two maize defence-related genes in specific seed tissues by RNAinsitu hybridization. Maize kernels were inoculated with either A.flavus or F.verticillioides 21-22 days after pollination, and harvested at 4, 12, 24, 48, 72, 96 and 120h post-inoculation. The fungi colonized all tissues of maize seed, but differed in their interactions with aleurone and germ tissues. RNAinsitu hybridization showed the induction of the maize pathogenesis-related protein, maize seed (PRms) gene in the aleurone and scutellum on infection by either fungus. Transcripts of the maize sucrose synthase-encoding gene, shrunken-1 (Sh1), were observed in the embryo of non-infected kernels, but were induced on infection by each fungus in the aleurone and scutellum. By comparing histological and RNAinsitu hybridization results from adjacent serial sections, we found that the transcripts of these two genes accumulated in tissue prior to the arrival of the advancing pathogens in the seeds. A knowledge of the patterns of colonization and tissue-specific gene expression in response to these fungi will be helpful in the development of resistance.
AB - Aspergillus flavus and Fusarium verticillioides are fungal pathogens that colonize maize kernels and produce the harmful mycotoxins aflatoxin and fumonisin, respectively. Management practice based on potential host resistance to reduce contamination by these mycotoxins has proven difficult, resulting in the need for a better understanding of the infection process by these fungi and the response of maize seeds to infection. In this study, we followed the colonization of seeds by histological methods and the transcriptional changes of two maize defence-related genes in specific seed tissues by RNAinsitu hybridization. Maize kernels were inoculated with either A.flavus or F.verticillioides 21-22 days after pollination, and harvested at 4, 12, 24, 48, 72, 96 and 120h post-inoculation. The fungi colonized all tissues of maize seed, but differed in their interactions with aleurone and germ tissues. RNAinsitu hybridization showed the induction of the maize pathogenesis-related protein, maize seed (PRms) gene in the aleurone and scutellum on infection by either fungus. Transcripts of the maize sucrose synthase-encoding gene, shrunken-1 (Sh1), were observed in the embryo of non-infected kernels, but were induced on infection by each fungus in the aleurone and scutellum. By comparing histological and RNAinsitu hybridization results from adjacent serial sections, we found that the transcripts of these two genes accumulated in tissue prior to the arrival of the advancing pathogens in the seeds. A knowledge of the patterns of colonization and tissue-specific gene expression in response to these fungi will be helpful in the development of resistance.
KW - Aspergillus flavus
KW - Fusarium verticillioides
KW - Histology
KW - Maize
KW - PRms
KW - RNAinsitu hybridization
KW - Sh1
UR - http://www.scopus.com/inward/record.url?scp=84937630553&partnerID=8YFLogxK
U2 - 10.1111/mpp.12224
DO - 10.1111/mpp.12224
M3 - Article
C2 - 25469958
AN - SCOPUS:84937630553
VL - 16
SP - 662
EP - 674
JO - Molecular Plant Pathology
JF - Molecular Plant Pathology
SN - 1464-6722
IS - 7
ER -