Table 1.

Transcriptional reprogramming of meristem switching and downstream floral organ identity genes in response to phytoplasma infection

Genes involved in floral signaling pathway		Previous reports				This study
		STOL-infected tomato (14)	OY-infected petunia (15)	Italian ICPh-infected Arabidopsis (17)	PLY- or PnWB- infected periwinkle (16)	PPT phytoplasma-infected tomato
						BB stages 3 and 6	CLI	DSGP	WB
Flower organ identity genes	Class A		PFG↓	AP1→		MC↓↓
	Class B	LeDEF↓	PhGLO1↓	AP3↓		LePI↓↓
				PI↓		TAP3↓↓
						TM6↓↓
						TPI↓↓
	Class C	TAG1↑↓	pMADS3↑	AG↓		TAG1↓↓
			FBP6↑			TAGL1↓↓
	Class D		FBP7↓			SLMBP3→↓↓*
						TAGL11↑↑↓*
	Class E		FBP2↑	SEP3↓	SEP3↓	LeMADS1↓↓
			FBP5↑			TM29↓↓
						SLMBP21↓↓
						TM5 (SEP3)↓↓
						RIN↓→
FM identity genes		FA↑	ALF↓			FA↓→	FA↓
		WUS↓	DOT↓			AN↓↓	AN↓
			TER↓			LeWUS↓↓	LeWUS→
IM identity genes						SFT→→	SFT↑	SFT↓
								SP→
Vegetative-inflorescence meristem integrity gene									LeWUS↓

Abbreviations: BB, big bud; CLI, cauliflower-like inflorescence; DSGP, disrupted sympodial growth pattern; ICPh, Italian clover phyllody; OY, onion yellows phytoplasma; PLY, periwinkle leaf yellowing phytoplasma; PnWB, peanut witches’-broom phytoplasma; PPT, potato purple top phytoplasma; STOL, stolbur phytoplasma; WB, witches’ broom. ↓, down-regulation; ↑, up-regulation; →, no apparent transcriptional change.

^*For RT-PCR assay of class D genes SLMBP3 and TAGL11, samples from stages 3, 6, and 8 were used. During the morphogenesis of tomato flowers, the initiation of ovule development from the placenta does not occur until stage 8 (34).