The identification of Cucumis sativus Glabrous 1 (CsGL1) required for the formation of trichomes uncovers a novel function for the homeodomain-leucine zipper I gene.
The spines and bloom of cucumber (Cucumis sativus L.) fruit are two important quality traits related to fruit market value. However, until now, none of the genes involved in the formation of cucumber fruit spines and bloom trichomes has been identified. Here, the characterization of trichome development in wild-type (WT) cucumber and a spontaneous mutant, glabrous 1 (csgl1) controlled by a single recessive nuclear gene, with glabrous aerial organs, is reported. Via map-based cloning, CsGL1 was isolated and it was found that it encoded a member of the homeodomain-leucine zipper I (HD-Zip I) proteins previously identified to function mainly in the abiotic stress responses of plants. Tissue-specific expression analysis indicated that CsGL1 was strongly expressed in trichomes and fruit spines. In addition, CsGL1 was a nuclear protein with weak transcriptional activation activity in yeast. A comparative analysis of the digital gene expression (DGE) profile between csgl1 and WT leaves revealed that CsGL1 had a significant influence on the gene expression profile in cucumber, especially on genes related to cellular process, which is consistent with the phenotypic difference between csgl1 and the WT. Moreover, two genes, CsMYB6 and CsGA20ox1, possibly involved in the formation of cucumber trichomes and fruit spines, were characterized. Overall, the findings reveal a new function for the HD-Zip I gene subfamily, and provide some candidate genes for genetic engineering approaches to improve cucumber fruit external quality.
State Key Laboratory of Crop Biology; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (Huanghuai Region), Ministry of Agriculture; College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an, Shandong 271018, PR China.
Qiang
Q
Li
State Key Laboratory of Crop Biology; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (Huanghuai Region), Ministry of Agriculture; College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an, Shandong 271018, PR China.
Chenxing
C
Cao
State Key Laboratory of Crop Biology; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (Huanghuai Region), Ministry of Agriculture; College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an, Shandong 271018, PR China.
Cunjia
C
Zhang
State Key Laboratory of Crop Biology; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (Huanghuai Region), Ministry of Agriculture; College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an, Shandong 271018, PR China.
Shuangshuang
S
Zheng
State Key Laboratory of Crop Biology; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (Huanghuai Region), Ministry of Agriculture; College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an, Shandong 271018, PR China.
Zenghui
Z
Wang
State Key Laboratory of Crop Biology; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (Huanghuai Region), Ministry of Agriculture; College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an, Shandong 271018, PR China.
Lina
L
Wang
State Key Laboratory of Crop Biology; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (Huanghuai Region), Ministry of Agriculture; College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an, Shandong 271018, PR China zhren@sdau.edu.cn.
Zhonghai
Z
Ren
D003001:Cloning, Molecular; D018553:Cucumis sativus / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D005638:Fruit / Q000033:anatomy & histology / Q000235:genetics / Q000378:metabolism; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D016350:Leucine Zippers / Q000502:physiology*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D064201:Trichomes / Q000254:growth & development / Q000648:ultrastructure
D018398:Homeodomain Proteins; D010940:Plant Proteins
Bloom; HD-Zip I; cucumber; map-based cloning; spine; trichome.