|ARRO, JIE - Oak Ridge Institute For Science And Education (ORISE)|
|CUENCA, JOSE - Oak Ridge Institute For Science And Education (ORISE)|
|LIANG, ZHENCHANG - Chinese Academy Of Sciences|
|COUSINS, PETER - E & J Gallo Winery|
Submitted to: Horticulture Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/7/2017
Publication Date: 7/12/2017
Citation: Arro, J., Cuenca, J., Yang, Y., Liang, Z., Cousins, P., Zhong, G. 2017. A transcriptome analysis of two grapevine populations segregating for tendril phyllotaxy. Horticulture Research. 4:11. doi:10.1038/hortres.2017.32.
Interpretive Summary: Grapevine (Vitis spp), belonging to the family Vitaceae, is one of the oldest domesticated fruit crops in the world. Except for a few, most species in the family Vitaceae possess tendrils and are known for their climbing habit. Tendril is a tactile string-like motile organ adapted for grappling and supporting the growing vine as it climbs atop canopies for maximum light interception in the wild. Tendrils are adaptive morphological innovation in plants. In Vitaceae, the tendril occupies a more significant biological role due to its close relationship with inflorescences. In the most widely cultivated Vitis species, Vitis vinifera, the tendril normally appears in repeating units of three nodes, opposite each leaf in two sequential nodes and then a skip on the third. However, there are exceptions or mutant types which are deviated from the normal distribution pattern. In this study, we studied tendril distribution in two vine populations segregating for the attribute by using a molecular profiling method called RNASeq. We found several interesting genes which might be involved in controlling tendril distribution patterns. Our results shed light on the molecular processes involved in the tendril development, helping develop further understanding of the genetic control of reproductive traits and related plant architecture in grapevine.
Technical Abstract: The shoot structure of cultivated grapevine Vitis vinifera L. typically exhibits a 3-node modular repetitive pattern, two sequential leaf-opposed tendrils followed by a tendril-free node. In this study, we investigated the molecular basis of this pattern by characterizing differentially expressed genes in 10 bulk samples of young tendril tissue from two grapevine populations showing segregation of mutant or wild-type shoot/tendril phyllotaxy. One population was the selfed progeny and the other one outcrossed progeny of a Vitis hybrid, ‘Roger’s Red’. We analyzed 13 375 expressed genes and carried out in-depth analyses of 324 of them which were differentially expressed with a minimum of 1.5 fold changes between the mutant and wild-type bulk samples in both selfed and cross populations. A significant portion of these genes were direct cis-binding targets of 14 transcription factor families that were themselves differentially expressed. Network-based dependency analysis further revealed that most of the significantly rewired connections among the ten most connected hub genes involved at least one transcription factor. TCP3 and MYB12, which were known important for plant form development, were among these TFs. More importantly, TCP3 and MYB12 were found in this study to be involved in regulating the lignin gene PRX52 which is important to plant form development. A further support evidence for the roles of TCP3-MYB12-PRX52 in contributing to tendril phyllotaxy was the findings of two other lignin-related genes uniquely expressed in the mutant phyllotaxy background.