Journal Article

putative positive feedback regulation mechanism in CsACS2 expression suggests a modified model for sex determination in cucumber (Cucumis sativus L.)

Li, Zheng, Si, Longting, Gong, Zhenhui, Tao, Qianyi, Wang, Shu, Pan, Junsong, Cai, Run

2012

Overview

It is well established that the plant hormone ethylene plays a key role in cucumber sex determination. Since the unisexual control gene M was cloned and shown to encode an ethylene synthase, instead of an ethylene receptor, the ‘one-hormone hypothesis’, which was used to explain the cucumber sex phenotype, has been challenged. Here, the physiological function of CsACS2 (the gene encoded by the M locus) was studied using the transgenic tobacco system. The results indicated that overexpression of CsACS2 increased ethylene production in the tobacco plant, and the native cucumber promoter had no activity in transgenic tobacco (PM). However, when PM plants were treated with exogenous ethylene, CsACS2 expression could be detected. In cucumber, ethylene treatment could also induce transcription of CsACS2, while inhibition of ethylene action reduced the expression level. These findings suggest a positive feedback regulation mechanism for CsACS2, and a modified ‘one-hormone hypothesis’ for sex determination in cucumber is proposed.

• Publisher: Oxford University Press [etc.],Oxford University Press
• Subject: Base Sequence / Biological and medical sciences / cucumbers / Cucumis sativus / Cucumis sativus - drug effects / Cucumis sativus - genetics / Cucumis sativus - growth & development / Cucumis sativus - physiology / DNA, Plant / DNA, Plant - genetics / drug effects / ethylene / ethylene production / Ethylenes / Ethylenes - metabolism / Ethylenes - pharmacology / Flowers / Flowers - drug effects / Flowers - genetics / Flowers - growth & development / Flowers - physiology / Fundamental and applied biological sciences. Psychology / Gametogenesis, Plant / Gametogenesis, Plant - drug effects / Gametogenesis, Plant - genetics / Gene Expression / Gene Expression Regulation, Plant / Gene Expression Regulation, Plant - drug effects / Gene Expression Regulation, Plant - genetics / gene overexpression / genes / genetics / growth & development / loci / metabolism / Models, Biological / Molecular Sequence Data / Nicotiana - drug effects / Nicotiana - genetics / Nicotiana - growth & development / Nicotiana - physiology / Organophosphorus Compounds / Organophosphorus Compounds - pharmacology / pharmacology / Phenotype / physiology / Plant Growth Regulators / Plant Growth Regulators - metabolism / Plant Growth Regulators - pharmacology / Plant Leaves / Plant Leaves - drug effects / Plant Leaves - genetics / Plant Leaves - growth & development / Plant Leaves - physiology / Plant physiology and development / Plant Proteins / Plant Proteins - genetics / Plant Proteins - metabolism / Plants, Genetically Modified / Promoter Regions, Genetic / Promoter Regions, Genetic - genetics / Research Paper / Seedlings / Seedlings - drug effects / Seedlings - genetics / Seedlings - growth & development / Seedlings - physiology / Sequence Analysis, DNA / sex determination / Silver Nitrate / Silver Nitrate - pharmacology / tobacco / transgenic plants