Physiological and nutritional alterations in virus-infected plants This update focuses on metabolic, physiological and elemental content alterations in the framework of virus plant interactions. Plant trascriptome analysis reveals that progression of viral infections follows a cyclic pattern, reflecting different steps of virus replication as well as disease symptoms appearance and regression. In the framework of a global cellular remodelling viral replication is hosted in spherules, vesicles, and/or multivesicular bodies, which are denoted as virus factories or viroplasms. Membrane and organelle alterations are due to the action of few multifunctional viral proteins, which act as a scaffold for the assembly of larger complexes including viral RNA and viral and host proteins. Such viroplasms seem to be also involved in cellto- cell virus transport and in confining RNA replication to keep it away from certain host defence mechanisms. Using cucurbits, grapevine and tomato as model plants it is shown that viral infection affects: i) sugar transport and the amounts of the various sugars in the phloem sap; ii) synthesis of carotenoids and iii) total organic acid contents. The virus-induced altered metabolism is usually accompanied by increased respiration and decreased photosynthetic rates and modifies host selection behaviour by its insect vector, according to the “vector manipulation hypothesis”. Finally an estimate is given of viral protein income as infected vegetables enter human diet.
Effetti delle infezioni virali sulla fisiologia e sul valore nutrizionale delle colture agrarie.
Spanò R.;MASCIA, TIZIANA;GALLITELLI, Donato
2013-01-01
Abstract
Physiological and nutritional alterations in virus-infected plants This update focuses on metabolic, physiological and elemental content alterations in the framework of virus plant interactions. Plant trascriptome analysis reveals that progression of viral infections follows a cyclic pattern, reflecting different steps of virus replication as well as disease symptoms appearance and regression. In the framework of a global cellular remodelling viral replication is hosted in spherules, vesicles, and/or multivesicular bodies, which are denoted as virus factories or viroplasms. Membrane and organelle alterations are due to the action of few multifunctional viral proteins, which act as a scaffold for the assembly of larger complexes including viral RNA and viral and host proteins. Such viroplasms seem to be also involved in cellto- cell virus transport and in confining RNA replication to keep it away from certain host defence mechanisms. Using cucurbits, grapevine and tomato as model plants it is shown that viral infection affects: i) sugar transport and the amounts of the various sugars in the phloem sap; ii) synthesis of carotenoids and iii) total organic acid contents. The virus-induced altered metabolism is usually accompanied by increased respiration and decreased photosynthetic rates and modifies host selection behaviour by its insect vector, according to the “vector manipulation hypothesis”. Finally an estimate is given of viral protein income as infected vegetables enter human diet.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
