Open AccessTransgenic alteration of ethylene biosynthesis increases grain yield in maize under field drought‐stress conditions
Author(s) -
Habben Jeffrey E.,
Bao Xiaoming,
Bate Nicholas J.,
DeBruin Jason L.,
Dolan Dennis,
Hasegawa Darren,
Helentjaris Timothy G.,
Lafitte Renee H.,
Lovan Nina,
Mo Hua,
Reimann Kellie,
Schussler Jeffrey R.
Publication year - 2014
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/pbi.12172
Subject(s) - biology , transgene , agronomy , genetically modified crops , abiotic stress , sowing , context (archaeology) , horticulture , gene , genetics , paleontology
Summary A transgenic gene‐silencing approach was used to modulate the levels of ethylene biosynthesis in maize ( Z ea mays L.) and determine its effect on grain yield under drought stress in a comprehensive set of field trials. Commercially relevant transgenic events were created with down‐regulated ACC synthases ( ACS s), enzymes that catalyse the rate‐limiting step in ethylene biosynthesis. These events had ethylene emission levels reduced approximately 50% compared with nontransgenic nulls. Multiple, independent transgenic hybrids and controls were tested in field trials at managed drought‐stress and rain‐fed locations throughout the US. Analysis of yield data indicated that transgenic events had significantly increased grain yield over the null comparators, with the best event having a 0.58 Mg/ha (9.3 bushel/acre) increase after a flowering period drought stress. A (genotype × transgene) × environment interaction existed among the events, highlighting the need to better understand the context in which the down‐regulation of ACS s functions in maize. Analysis of secondary traits showed that there was a consistent decrease in the anthesis‐silking interval and a concomitant increase in kernel number/ear in transgene‐positive events versus nulls. Selected events were also field tested under a low‐nitrogen treatment, and the best event was found to have a significant 0.44 Mg/ha (7.1 bushel/acre) yield increase. This set of extensive field evaluations demonstrated that down‐regulating the ethylene biosynthetic pathway can improve the grain yield of maize under abiotic stress conditions.