Table 1.

State of progress in the application of genetic engineering techniques outside Italy. Many studies report the applications of new genomics techniques and Agrobacterium-mediated transformation using several types of starting explants that are mainly focused on the introduction of resistance to biotic and abiotic stresses in Citrus, Vitis, Castanea, and Malus. In other species such as kiwifruit and strawberries, most recent studies are mainly directed toward the improvement of traits linked to yields and early flowering.

Genus	Species	Trait	Modified Gene(s)	Approach	Ref.
Citrus	C. sinensis	Resistance to Citrus canker disease	Loss of function of CsNPR3 that represses NPR1	CRISPR/Cas9; Protoplast transfection with Lipofectamine	[20]
	C. paradisi		Mutation of an EBE in the promoter of LOB1	CRISPR/Cas9; A. tumefaciens infection of grapefruit epicotyls	[21]
	C. sinensis		Mutation of an EBE in the promoter of LOB1	CRISPR/Cas9; A. tumefaciens infection of epicotyls and protoplast transfection. Improved binary vector	[21]
	C. paradisi C. sinensis × Poncirus trifoliata		Loss of function of DMR6	CRISPR/Cas9; A. tumefaciens infection of epicotyls	[22]
Vitis	V. vinifera	Resistance to Botrytis cinerea	Loss of function of VvWRKY52	CRISPR/Cas9; A. tumefaciens infection of embryogenic callus	[23]
	V. vinifera	Tolerance to downy mildew caused by Plasmopara viticola	Loss of function of PR4	CRISPR/Cas9; A. tumefaciens infection of embryogenic callus	[24]
	V. vinifera	Resistance to powdery mildew caused by Erysiphe necator	Loss of function of VvMLO3 and VvMLO4	CRISPR/Cas9; A. tumefaciens infection of embryogenic callus	[25]
	V. riparia × V. rupestris	Tolerance to Pierce’s disease and Red Blotch Disease	Disruption of the miRNA gene TAS4a/b	CRISPR/Cas9; A. tumefaciens infection of embryogenic callus	[26]
	V. vinifera × V. berlandieri	Control of grapevine shoot branching	Loss of function of CCD7 and CCD8	CRISPR/Cas9; A. tumefaciens infection of embryogenic callus	[27]
	V. amurensis	Response to cold stress	Loss of function of PAT1	CRISPR/Cas9; A. tumefaciens infection of embryogenic callus	[28]
Castanea	C. sativa	Tolerance to Chestnut blight	Overexpression of the CsCh3	Agrobacterium-mediated transformation of somatic embryos	[29]
	C. dentata		Overexpression of the wheat OxO	Agrobacterium-mediated transformation of somatic embryos	[30]
Malus	Malus × domestica	Tolerance to Botryosphaeria dothidea	Loss of function of CNGC	CRISPR/Cas9; A. tumefaciens infection of leaf explants	[31]
	Malus × domestica	Early flowering	Loss of function of TFL1	CRISPR/Cas9; A. tumefaciens infection of leaf explants	[32]
	Malus × domestica	Proof of concept of base editing application	Base editing of ALS and PDS	CRISPR/Cas9; A. tumefaciens infection of leaf explants	[33]
	M. sieversii		Knockout of PDS	CRISPR/Cas9; A. tumefaciens infection of leaf explants	[34]
Pyrus	P. communis	Early flowering	Loss of function of TFL1	CRISPR/Cas9; A. tumefaciens infection of leaf explants	[32]
	P. communis	Proof of concept of base editing application	Base editing of ALS and PDS	CRISPR/Cas9; A. tumefaciens infection of leaf explants	[33]
Fragaria	F. vesca	Investigation of the auxin synthesis sites during fruit and root development	Loss of function of FveYUC10	CRISPR/Cas9; A. tumefaciens infection of leaf strips	[35]
Actinidia	A. chinensis	Compactness of growth habit, early flowering, and fruit development	Loss of function of AcCEN4 and AcCEN	CRISPR/Cas9; A. tumefaciens-mediated transformation of leaf explants	[36]
	A. chinensis	Self-pollination and fast-flowering offspring.	Loss of function of SyGl and CEN-like genes	CRISPR/Cas9; A. tumefaciens-mediated transformation of leaf explants	[37]
	A. chinensis	Evergrowing but not early flowering phenotype	Genome editing of AcBFT2	CRISPR/Cas9; A. tumefaciens-mediated transformation of leaf explants	[38]