24-Epibrassinolide mitigates nickel toxicity in young Eucalyptus urophylla S.T. Blake plants: nutritional, physiological, biochemical, anatomical and morphological responses

Table 6 Stomatal characteristics and leaf anatomy in young Eucalyptus urophylla plants sprayed with EBR and exposed to Ni toxicity

Ni	EBR	SD (stomata per mm²)		PDS (μm)		EDS (μm)		SF		SI (%)
Adaxial face
−	−	221a		11.5c		17.1c		0.67b		7.8a
−	+	230a	4%	10.5d	− 9%	14.9d	− 13%	0.71a	6%	8.1a	4%
+	−	116c		13.7a		21.6a		0.63c		6.8c
+	+	185b	59%	12.8b	− 7%	19.3b	− 11%	0.66b	5%	7.2b	6%
Abaxial face
−	−	657a		10.1c		14.4c		0.71a		18.3a
−	+	678a	3%	9.7c	− 4%	13.7c	− 5%	0.72a	1%	18.7a	2%
+	−	600c		13.2a		20.5a		0.64c		15.3c
+	+	628b	5%	12.6b	− 5%	19.1b	− 7%	0.67b	5%	16.8b	10%
Leaf anatomy
Ni	EBR	ETAd (μm)		ETAb (μm)		PPT (μm)		SPT (μm)		Ratio PPT/SPT
−	−	19.2a		15.9b		65a		99a		0.66b
−	+	20.8a	8%	17.2a	8%	66a	2%	103a	4%	0.64b	−3%
+	−	16.3b		13.6c		56b		73 ± 1c		0.77a
+	+	17.1b	5%	14.7c	8%	61a	9%	82b	12%	0.75a	−3%

SD = Stomatal density; PDS = Polar diameter of the stomata; EDS = Equatorial diameter of the stomata; SF = Stomatal functionality; SI = Stomatal index; ETAd = Epidermis thickness from adaxial leaf side; ETAb = Epidermis thickness from abaxial leaf side; PPT = Palisade parenchyma thickness; SPT = Spongy parenchyma thickness. Comparison with similar treatment without EBR. Columns with different letters indicate significant differences from the Scott-Knott test (P < 0.05). Values described corresponding to means from five repetitions and standard deviations

ISSN: 1297-966X