Table 1.

Representative physiological and molecular processes readily visualized in vivo using various imaging methods

Parameter		Process	Wavelength	Reference
Photosynthesis	Fv/Fm	Maximum quantum efficiency of PSII	470/700	Genty et al., 1989; Rolfe and Scholes, 1995;
	NPQ	Non-photochemical energy dissipation		Oxborough, 2004
	ΦPSII	Quantum yield of electron transport
Water and energy status	Thermal	Transpiration, conductance	None/ >1200	Jones, 1999; Omasa and Takayama, 2003
	MRI	Water transport	X-rays and microwaves	Gussoni et al., 2001, Clearwater and Clark, 2003
	Tracers		Depends on tracer	Gaff and O-Ogoloa, 1971; Canny, 1990
Leaf pigments	NDVI	Chlorophyll content	<700/750, 704	Gamon and Surfus, 1999
	Red/green	Anthocyanin content	<700/600–699, 500–599
	PRI	Xanthophyll cycle	<700/531, 570
Molecular interactions and cell environment	GFP	Gene expression, protein motility, organelle location, cellular pH	485/509	Buschmann et al., 2000; Dixit et al., 2006
	RFP		490, 520, 563/583
	BFP		UV/440
Defence compounds	Dyes	Reactive oxygen species, Ca2+	400–700	Fryer et al., 2002; Maffei et al., 2004
Metabolites	Beta emission	Carbohydrate/metabolite transport	Autoradiography	Minchin and Thorpe 2003; Thorpe et al., 2007

Where appropriate, the excitation and measurements wavelengths are noted (wavelength: excitation/measurement).

Modified from Aldea et al. (2006a).