Table 2.

List of phytohormone signal components in leaf senescence and plant immunity.

Hormone	Component	Function	AGI Code	Role in Leaf Senescence	Role in Resistance a	Role in Resistance b
ET	EIN2	Involved in ethylene signal transduction	AT5G03280	Positive [100]	Ambiguous [42,101,102]	Negative [103]
	EIN3	Key transcription factor that initiates downstream transcriptional cascades for ethylene responses	AT3G20770	Positive [100]	Negative [102]	Positive [104]
	EIL1	EIN3-like 1	AT2G27050	Positive [100]	Negative [102]	Positive [104]
JA	COI1	Key component required for JA-induced transcriptional regulation	AT2G39940	Positive [105,106]	Negative [107]	Positive [21,108] Negative [103,109]
	JAZ7	Protein constitutes JA receptor complex with COI1	AT2G34600	Negative [110]	Positive [111]	Negative [111]
	MYC2	A MYC-related transcriptional activator interacted with JAZs	AT1G32640	Positive [112]	Negative [113]	Negative [114,115]
SA	ICS1	Required for SA biosynthesis	AT1G74710	Positive [5]	Positive [15]	Non [18]
	NPR1	Key regulator of SA-mediated disease resistance	AT1G64280	Positive [22]	Positive [20]	Non [21]
	EDS1	Component of R gene-mediated disease resistance	AT3G48090	Positive [22,25]	Positive [23]	Negative [24]
	PAD4	A lipase-like protein that is important for SA signaling.It can interact with EDS1	AT3G52430	Positive [22,25]	[23]
ABA	PYL9	ABA receptor	AT1G01360	Positive [116]
	SnRK2.8	A member of SNF1-related protein kinase involved in ABA signaling	AT1G78290	Positive [116]	Positive [117]
	ABI5	A bZIP transcription factor involved in ABA signaling	AT2G36270	Positive [118]		Non [81]
GA	DELLAs	Repressor of GA responses and involved in GA-mediated signaling	AT1G14920	Negative [119]	Negative [120]	Positive [120]
CK	AHK3	Cytokinin receptor	AT1G27320	Positive [121]	Positive [122]
	ARR2	A transcription factor involved in the cytokinin signaling pathway	AT4G16110	Non [123]	Positive [122]
Auxin	TIR1	Auxin receptor	AT3G62980	Positive [124]
	ARF2	An auxin response factor	AT5G62000	Positive [125,126]
BR	BRI1	A plasma membrane localized leucine-rich repeat receptor kinase involved in brassinosteroid signal transduction	AT4G39400	Positive [11]		Negative [127]

^a Resistance ability to biotrophic and hemi-biotrophic pathogens. ^b Resistance ability to necrotrophic pathogens.