Gibberellins (GAs) play important roles in the regulation of plant growth and development. The green revolution gene SD1 encoding gibberellin 20-oxidase 2 (GA20ox2) has been widely used in modern rice breeding. However, the molecular mechanism of how SD1/OsGA20ox2 expression is regulated remains unclear. Here we report a Cys2/His2 zinc finger protein ZFP207 acting as a transcriptional repressor of OsGA20ox2. ZFP207 was mainly accumulated in young tissues and more specifically in culm nodes. ZFP207-overexpression (ZFP207OE) plants displayed semi-dwarfism phenotype and small grains by modulating cell length. RNA interference of ZFP207 caused increased plant height and grain length. Application of exogenous GA3 could rescue the semi-dwarf phenotype of ZFP207OE rice seedlings. Moreover, ZFP207 repressed the expression of OsGA20ox2 via binding to its promoter region. Taken together, ZFP207 acts as a transcriptional repressor of SD1/OsGA20ox2 and it may play a critical role in plant growth and development through fine-tuning GA biosynthesis in rice.
We studied the salt stress tolerance of two accessions isolated from different areas of the world (Norway and Tunisia) and characterized the mechanism(s) regulating salt stress in Brachypodium sylvaticum Osl1 and Ain1. Perennial grasses are widely grown in different parts of the world as an important feedstock for renewable energy. Their perennial nature that reduces management practices and use of energy and agrochemicals give these biomass crops advantages when dealing with modern agriculture challenges such as soil erosion, increase in salinized marginal lands and the runoff of nutrients. Brachypodium sylvaticum is a perennial grass that was recently suggested as a suitable model for the study of biomass plant production and renewable energy. However, its plasticity to abiotic stress is not yet clear. We studied the salt stress tolerance of two accessions isolated from different areas of the world and characterized the mechanism(s) regulating salt stress in B. sylvaticum Osl1, originated from Oslo, Norway and Ain1, originated from Ain-Durham, Tunisia. Osl1 limited sodium transport from root to shoot, maintaining a better K/Na homeostasis and preventing toxicity damage in the shoot. This was accompanied by higher expression of HKT8 and SOS1 transporters in Osl1 as compared to Ain1. In addition, Osl1 salt tolerance was accompanied by higher abundance of the vacuolar proton pump pyrophosphatase and Na/H antiporters (NHXs) leading to a better vacuolar pH homeostasis, efficient compartmentation of Na in the root vacuoles and salt tolerance. Although preliminary, our results further support previous results highlighting the role of Na transport systems in plant salt tolerance. The identification of salt tolerant and sensitive B. sylvaticum accessions can provide an experimental system for the study of the mechanisms and regulatory networks associated with stress tolerance in perennials grass.
Gibberellins (GAs) play important roles in the regulation of plant growth and development. The green evolution gene SD1 encoding gibberellin 20-oxidase 2 (GA20ox2) has been widely used in modern rice breeding. However, the molecular mechanism of how SD1/OsGA20ox2 expression is regulated remains unclear. Here we report a Cys2/His2 zinc finger protein ZFP207 acting as a transcriptional repressor of OsGA20ox2. ZFP207 was mainly accumulated in young tissues and more specifically in culm nodes. ZFP207-overexpression (ZFP207OE) plants displayed semi-dwarfism phenotype and small grains by modulating cell length. RNA interference of ZFP207 caused higher plant and longer grains. The endogenous bioactive GA levels were significantly reduced in ZFP207OE plants and application of exogenous GA 3 rescued the semi-dwarf phenotype. The in vivo and in vitro studies showed that ZFP207 repressed the expression of OsGA20ox2 via binding to its promoter region. Together, ZFP207 acts as a transcriptional repressor of gibberellins biosynthesis and it may play a critical role in plant growth and development through fine-tuning GA biosynthesis in rice.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.