RBCS1 expression in coffee: Coffea orthologs, Coffea arabica homeologs, and expression variability between genotypes and under drought stress

Table 5 The expression levels of CaCc and CaCe isoforms in leaves of eight-year-old C. arabica.

	WT	Y	RQ_Cc	RQ_Ce	RQ_RBCS1-T	Cc/Ce
		U1-08	21.65	6.22	27.87	3.48
	I	WS-08	6.95	8.99	15.94	0.77
I59		U2-08	35.17	6.21	41.38	5.66
		U1-08	20.56	5.46	26.03	3.76
	NI	WS-08	11.74	1.60	13.34	7.33
		U2-08	24.19	9.35	33.54	2.59
		U1-08	-	11.58	11.58	-
	I	WS-08	-	10.38	10.38	-
Rubi		U2-08	-	8.00	8.00	-
		U1-08	-	15.99	15.99	-
	NI	WS-08	-	9.52	9.52	-
		U2-08	-	12.46	12.46	-
	WT	Y	RQ _Cc	RQ _Ce	RQ _RBCS1-T	Cc / Ce
		U1-08	14.62	7.18	21.80	2.03
	I	WS-08	19.55	6.04	25.59	3.23
I59		U2-08	25.90	11.81	37.72	2.19
	NI	U1-08	35.32	8.16	43.48	4.33
		WS-08	17.68	6.12	23.80	2.89
		U2-08	19.62	6.65	26.26	2.95
		U1-08	-	7.21	7.21	-
	I	WS-08	-	8.30	8.30	-
Rubi		U2-08	-	8.79	8.79	-
		U1-08	-	14.05	14.05	-
	NI	WS-08	-	7.16	7.16	-
		U2-08	-	8.12	8.12	-

Leaves of the cultivars I59 and Rubi were harvested in daytime (top: between 10:00 and noon) or night time (bottom: between 3:00 and 5:00 am). The points of analysis were before (U1, unstressed), during (WS, water stress) and after (U2, unstressed) the dry season of 2008. Corresponding predawn leaf water potentials (Ψ_pd) are given in the Table 3. The results of the relative quantification (RQ) are given for the cultivars IAPAR59 (I59) and Rubi grown in the field with (I) or without (NI) irrigation during the dry season (WT: water treatment). RBCS1 targets corresponded to CaCe (Ce) and CaCc (Cc) amplified by the E18244 and C18244 primer pairs (Table 1), respectively. Total RBCS1 expression (RQ_RBCS1-T) corresponded to RQ_Cc+ RQ_Ce, while Cc/Ce ratios corresponded to the RQ_Cc /RQ_Ceratios. For the Rubi cultivar, CaCc gene expression was not detected (-). Results were normalised using the expression of the GAPDH reference gene.

ISSN: 1471-2229