Open Access
Defensin promoters as potential tools for engineering disease resistance in cereal grains
Author(s) -
Kovalchuk Nataliya,
Li Ming,
Wittek Finni,
Reid Nicolas,
Singh Rohan,
Shirley Neil,
Ismagul Ainur,
Eliby Serik,
Johnson Alex,
Milligan Andrew S.,
Hrmova Maria,
Langridge Peter,
Lopato Sergiy
Publication year - 2010
Publication title -
plant biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.525
H-Index - 115
eISSN - 1467-7652
pISSN - 1467-7644
DOI - 10.1111/j.1467-7652.2009.00465.x
Subject(s) - biology , promoter , defensin , anthesis , transgene , genetically modified rice , vascular bundle , germination , gene , genetically modified crops , arabidopsis , botany , genetics , gene expression , cultivar , mutant
Summary Engineering of plant protection in cereals requires well characterized tissue‐specific and wounding/pathogen‐inducible promoters for targeted expression of pathogen responsive and resistance genes. We describe the isolation of seven wheat and rice defensin genes expressed in early developing grain and during grain germination, two developmental stages that are particularly vulnerable to pathogens and insects. Comparison of three‐dimensional (3D) models of these rice and wheat PRPI defensins indicated variations in spatial architectures that could reflect their functional diversities. Wheat and rice were stably transformed with promoter–GUS fusion constructs and the spatial and temporal activities of four promoters were studied using whole‐mount and histological assays. PRPI promoters were active before and at anthesis in both transgenic wheat and rice with activity mainly in the ovary. In rice, GUS activity was also observed in vascular tissue of the lemma, palea and anthers. After fertilization, GUS was strongly expressed in the outer cell layers of the pericarp and in the main vascular bundle of the grain. During, and a short time after, seed germination, wheat promoters were active in transgenic rice embryos, roots and/or coleoptiles. All wheat and rice promoters were strongly induced by wounding in leaf, stem and grain of transgenic rice plants. These results suggest that PRPI promoters will be useful for specific targeting and accumulation of proteins conferring resistance to pathogens in vulnerable tissues of developing and germinating grain.