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Identifier

uch.biology.phd//2002kontodimou

Title

Μελέτη της λειτουργίας της πρωτεΐνης της ντομάτας LeRpt5 (LeMA-1 Lycopersicon esculentum Mg- dependent ATPase-1), σε φυτά

Alternative Title

Functional study of the tomato protein LeRpt5 (LeMA-1 Lycopersicon esculentum Mg-dependent ATPsae-1) in plants

Author

Κοντοδήμου, Αργυρώ Α

Abstract

Tomato protein LeMA-1 is a member of a new family of Mg-dependent ATPases called AAA protein family, and specifically member of the subgroup of the regulatory particle triple A ATPases (Rpts) of the 26S protease complex. The protein is located in the nucleus and is expressed in all plant tissues examined (tomato). This work is the first report of an in vivo study of one of these proteins in whole organism (apart from yeast). The code region of LeMA-1 was cloned onto the genome of the Potato virus X PVX) and the construct was used to inoculate plants (tomato, Nic. Benthamiana and Nic. Clevelandi). The plants that were infected with virus carrying LeMA-1 sequences developed a lethal phenotypewith characteristic symptoms: growth arrest, epinasty of shoots and distortion of the newly emerging leaves, which 15 days post infection lead to plant death. Constructs carrying the whole coding sequences as well as those carrying different deletion fragments of LeMA-1, both exhibited the same sequence of events after infection. Viruses trigger RNA silencing in infected plants (VIGS virus induced gene silencing). When they carry endogenous sequences then the insert the endogenous gene- is attacked by RNA silencing as well, which in the case of LeMA-1 caused the observed lethal phenotype. Based on these results it was estimated that this tool could be applied to study the phenotype caused by the expression of the other Rpts via PVX. For this purpose, parts of the coding sequences of four Rpts of tomato (the clones were obtained from a sequence bank) were cloned onto PVX and the constructs were used to inoculate plants. Of these, the PVX-Rpt1 construct was infectious and caused a lethal phenotype, whith symptoms less severe than the ones observed with the LeMA-1 constructs. The Rpt1 plants were arrested, the symptoms affected the newly emerging leaves which were distorted as well as the shoots but to a lesser extend compared with the LeMA-1 phenotype.

Language

Greek

Subject

ΑΑΑ πρωτείνες; Πρωτεάσωμα; Ιός της πατάτας Χ; Σίγηση γονιδίων μέσω ιών; Ιικός φορέας; πρωτεάση

Issue date

2002-12-13

Date available

2003-02-18

Collection

School/Department--School of Sciences and Engineering--Department of Biology--Doctoral theses

Type of Work--Doctoral theses

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