TABLE 1.

Detection of PPV in upper noninoculated leaves of transgenic tobacco plants at different days postinoculation

Transgenic line	15 d.p.i.			30 d.p.i.			45 d.p.i.			60 d.p.i.
	No. of plants with PPV/no. of inoculated plantsa	Position of highest leaf with virusb	Plant sizec	No. of plants with PPV/no. of inoculated plants	Position of highest leaf with virus	Plant size	No. of plants with PPV/no. of inoculated plants	Position of highest leaf with virus	Plant size	No. of plants with PPV/no. of inoculated plants	Position of highest leaf with virus	Plant size
U6B			3-4	2/8	5	8	4/8	7	12	1/8	7	16
1031-1XB	6/8	6	10-11	7/8	6	14-15			24/26			36
1031-2XC	7/8	6	5-6	8/8	9	9-12	6/8	11	16/17	6/8	14	20-26
1031-3XE	8/8	8	8-10	8/8	12-13	14-15	8/8	15	24/26	7/8	20	34
1210-6XI			6			11	7/8	NDd	ND	2/8	ND	ND
1115-1XK-1			10-11			16-20			22/31			39
1115-3XK-2			10-11			17-19			26/33			39
Vector trans.			7-8			17-20			28/30			28-30
Xanthi nc			7-8			12-14			25/29			35

^aAs shown by ELISA.

^bPosition above the three inoculated ones of the highest leaf showing PPV.

^cTotal number of leaves above the three inoculated ones.

^dND, not determined; upper leaves budded as bunches, preventing a confident assessment of leaf positions.