Periodic Reporting for period 2 - ROOT BARRIERS (Molecular mechanisms controlling endodermis and exodermis differentiation in tomato roots)
Reporting period: 2018-02-15 to 2019-02-14
Nevertheless, to date, the molecular players which control exodermis differentiation remain unknown as well as whether the regulatory programs that determine endodermis and exodermis development are the same or distinct. The ROOT BARRIERS project has addressed these questions with the study of endodermis and exodermis differentiation in tomato, a plant species that develops both layers. We have studied the exodermis and endodermis differentiation using the domesticated Solanum lycopersicum ´M82´ and wild Solanum pennellii species as they have different root morphology and cellular development and have found they differs in their differentiation features. Moreover, our results suggest the endodermis and exodermis differentiation in tomato do not share same molecular regulators. Some studies have revealed that endodermis and exodermis differentiation occurs precociously in response to salt stress. The ROOT BARRIERS project has aimed to study how salt stress affects endodermis and exodermis differentiation in tomato roots also using S. lycopersicum ´M82´and S. pennellii. In addition, the role of these two cell types is of special interest as S.pennellii is salt tolerant specie and suggests that the environment is able to directly regulate the development of a specific cell type. We have generated stable transgenics plants to isolate the messenger RNA specifically from the endodermis and exodermis in control and salt stress conditions. This way we will be able to identify the regulators implicated in the differentiation of these two cell types and how salt stress is influencing the control of their differentiation at the molecular level.
- Expression pattern of SlCASPs, SlSGN3, SlCIF2, SlMYB36 genes in the tomato root.
- Localization of the SlCASP proteins in the tomato root.
- Developmental framework for the endodermis and exodermis differentiation in Solanum lycopersicum and Solanum pennelli in control and salt stress conditions.
- Identification of an exodermis specific promoter.
- Generation of INTACT and TRAP lines to profile the mRNA from the endodermis and exodermis in Solanum lycopersicum and Solanum pennelli.
- Testing the apoplastic pathway in the exodermis and endodermis using specific tracers.
- CRISPR mutants for candidate genes potentially implicated in the endodermis and exodermis differentiation.
- Endodermis and Exodermis transcript profiling in control and salt stress conditions.
- There are different developmental frameworks for the endodermis and exodermis differentiation in tomato.
- None of the Arabidopsis molecular players, which control endodermis differentiation, homologs in tomato show a specific expression pattern in the endodermis or exodermis, as they are at least being expressed in both. Some of them are also expressed in the cortex and epidermis cells.
- We have identified an exodermis specific promoter. We will be able to specifically profile the mRNA form the exodermis cells using the INTACT and TRAP protocols.
- Salt stress is affecting differentially root development, the endodermis and exodermis differentiation in Solanum lycopersicum and Solanum pennelli.
- The exodermis in tomato shows a plastic response in the formation of the apoplastic barriers in salt stress conditions.
Exploitation and dissemination of the results
The results of the Root Barriers project were presented in the following conferences:
- Poster presentation. 8th International Symposium of Root development. Umea (Sweden, 2017)
- Poster presentation. FASEB meeting. Vermont (USA) (2017)
- Oral presentation. Plant Development and drought stress. Asilomar (USA) (2017)
- Poster presentation. XIV Reunión de Biología Molecular de Plantas. Salamanca. (Spain) (2018).
- Poster presentation. ISRR 10th International Symposium. Israel (2018).