Premium
Ectopic expression of ARGOS 8 reveals a role for ethylene in root‐lodging resistance in maize
Author(s) -
Shi Jinrui,
Drummond Bruce J.,
Habben Jeffrey E.,
Brugire Norbert,
Weers Ben P.,
Hakimi Salim M.,
Lafitte H. Renee,
Schussler Jeffrey R.,
Mo Hua,
Beatty Mary,
ZastrowHayes Gina,
O'Neill Dennis
Publication year - 2019
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.14131
Subject(s) - ethylene , nodal , biology , primordium , transgene , transcriptome , lateral root , ectopic expression , genetically modified crops , nodal signaling , gene , horticulture , gene expression , microbiology and biotechnology , botany , arabidopsis , genetics , biochemistry , mutant , gastrulation , embryogenesis , catalysis
Summary Ethylene plays a critical role in many diverse processes in plant development. Recent studies have demonstrated that overexpression of the maize ARGOS 8 gene reduces the plant's response to ethylene by decreasing ethylene signaling and enhances grain yield in transgenic maize plants. The objective of this study was to determine the effects of ethylene on the development of nodal roots, which are primarily responsible for root‐lodging resistance in maize. Exogenous application of the ethylene precursor 1‐aminocyclopropane‐1‐carboxylic acid ( ACC ) was found to promote the emergence of nodal roots. Transcriptome analysis of nodal tissues revealed that the expression of genes involved in metabolic processes and cell wall biogenesis was upregulated in response to ACC treatment, supporting the notion that ethylene is a positive regulator for the outgrowth of young root primordia. In BSV :: ARGOS 8 transgenic plants with reduced ethylene sensitivity due to constitutive overexpression of ARGOS 8 , nodal root emergence was delayed and the promotional effect of ACC on nodal root emergence decreased. Field tests showed that the BSV :: ARGOS 8 plants had higher root lodging relative to non‐transgenic controls. When ARGOS 8 expression was controlled by the developmentally regulated promoter FTM 1, which conferred ARGOS 8 overexpression in adult plants but not in the nodal roots and nodes in juvenile plants, the FTM 1:: ARGOS 8 plants had no significant difference in root lodging compared with the wild type but produced a higher grain yield. These results suggest that ethylene has a role in promoting nodal root emergence and that a delay in nodal root development has a negative effect on root‐lodging resistance in maize.