DTA

Digital Theses Archive

 

Tesi etd-05022018-195859

Type of thesis
Perfezionamento
Author
NERI, ANDREA
URN
etd-05022018-195859
Title
Study of molecular and physiological responses on Populus alba L. ‘Villafranca’ clone stressed with Cd and Zn.
Scientific disciplinary sector
BIO/04
Course
SCIENZE AGRARIE E BIOTECNOLOGIE - Agrobiosciences
Committee
relatore Prof. SEBASTIANI, LUCA
Membro Prof. PE', MARIO ENRICO
Keywords
  • aquaporin
  • arsenic
  • cadmium
  • ionomic
  • metal transporter
  • poplar
  • silicon
  • stress
  • xylem traits
  • zinc
Exam session start date
;
Availability
parziale
Abstract
The aims of this doctorate were to understand the metal distribution, homeostasis, and influence on plant physiology of wt and aqua1 line of Populus alba L. ‘Villafranca’ clone under Cd and Zn excesses. In particular, the PhD thesis focus on the aquaporin overexpression effect on metal homeostasis and plant resistance to metal excess. <br>First of all, wt and aqua1 lines have been tested to highlight differences in xylem traits analysing vessel diameter distribution, vessel area, vessel length, fibre length and cell wall composition (1st experiment). <br>Secondly, Cd distribution and its effect on plant physiology has been evaluated in both lines, wt and aqua1, under Cd stress (2nd experiment). In this work we analysed the gene expression of transporters involved in the translocation and compartmentalization of divalent cations to evaluate the effect of the gene expressions modification during Cd response at three different timings from the application of the metal stress.<br>Then, wt and aqua1 lines have been evaluated under mid-term Zn stress to highlight different responses (3rd experiment). In this work, we measured photosystem II efficiency, gas exchanges, water potential and water contents, xylem traits. To better highlight the differences, the plants were treated for 73 days, adding also weekly physiological measurements, to clarify if aquaporin overexpression gave an increased resistance to the metal stress.<br>At least, we decided to deepen the knowledge of mineral element uptake in the root. In particular, we studied the effect Si pre-treatment to alleviate Cd, and Si + Cd effect on the mineral element homeostasis through ICP-MS, and root characterization by confocal microscopy (4th experiment). The choice to use Si as treatment was due to its role as protecting molecule against metal stress.
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