Patró espacio-temporal de la ligno-suberificació de l’arrel d’Arabidopsis: la funció de les CASPARIAN STRIP MEMBRANE DOMAIN PROTEINS-LIKE en l’endodermis i el fel·lema
ENG- Terrestrial plants develop cellular barriers in stems and roots to protect themselves from adverse environmental conditions. These barriers accumulate lignin and suberin in their walls. Lignin is a polyphenolic polymer and suberin is an aliphatic polyester, and together, they provide rigidity,...
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| Format: | doctoral thesis |
| Status: | Published version |
| Publication Date: | 2024 |
| Country: | España |
| Institution: | CBUC, CESCA |
| Repository: | TDR. Tesis Doctorales en Red |
| OAI Identifier: | oai:www.tdx.cat:10803/692585 |
| Online Access: | http://hdl.handle.net/10803/692585 |
| Access Level: | Embargoed access |
| Keyword: | Suberina Lignina Lignin Arabidopsis Arrels Raíces Roots Fel·lema Felema Phellema Endodermis Periderm Periderma Casparian strip membrane domain protein (CASPs) 575 577 58 |
| Summary: | ENG- Terrestrial plants develop cellular barriers in stems and roots to protect themselves from adverse environmental conditions. These barriers accumulate lignin and suberin in their walls. Lignin is a polyphenolic polymer and suberin is an aliphatic polyester, and together, they provide rigidity, impermeability, and resistance to the cell walls. The endodermis and phellem are examples of ligno-suberized protective barriers, which we have studied in the roots of Arabidopsis, a model plant in plant research. The endodermis is found inside young roots and forms a barrier that controls the absorption of water and solutes, prevents them from returning to the soil during transport to the aerial part, and blocks the entry of toxic elements such as salt. In the more mature regions of the roots, where the endodermis is no longer present, the phellem covers the root to protect it from desiccation and pathogens. Using the endodermis and phellem of Arabidopsis roots as a model, we have discovered that the accumulation of lignin and suberin follows a temporal pattern and that these polymers are deposited in different layers of the cell wall. Additionally, we have identified the differences between the two tissues in the chemical composition of suberin. Next, we studied the function of a group of proteins called CASPARIAN STRIP MEMBRANE DOMAIN PROTEINS-LIKE (CASPLs). Through genetic engineering, we found that these proteins are activated in the endodermis and phellem when suberin accumulation begins. Using mutant plants without active CASPLs genes, we analysed how suberin and lignin are deposited. We demonstrated that the absence of CASPLs proteins alters the composition of the cell walls of the endodermis and phellem, making the plants more sensitive to growth in saline conditions. These results provide new insights into the ligno-suberization process, essential for the future development of plant varieties more tolerant to adverse environmental conditions |
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