Table I.

ZmPIP RNA expression

Comparison of the expression level of PIP genes in both genotypes was expressed as the ratio of the normalized signals (Penjalinan/Z7) at time 0. The RNA expression variation during cold stress was expressed as the ratio of the signal values obtained at time 0 and time 1 d or 3 d for both genotypes.

Aquaporin	Expression Levels (Penjalinan/Z7) at 0 d	Fold Change
		Penjalinan		Z7
		0/1 d	0/3 d	0/1 d	0/3 d
ZmPIP1;1	2.14	0.88	0.20	0.40	0.17
ZmPIP1;2	1.36	0.93	0.31	0.71	0.40
ZmPIP1;3	1.44	0.55	0.16	0.54	0.29
ZmPIP1;4	1.14	0.81	0.25	0.46	0.23
ZmPIP1;5	0.78	0.74	0.32	0.38	0.26
ZmPIP1;6	2.70	0.60	0.35	0.56	0.89
ZmPIP2;1	1.08	0.88	0.20	0.79	0.40
ZmPIP2;2	1.13	0.73	0.27	0.44	0.40
ZmPIP2;3	0.99	0.94	0.14	0.47	0.42
ZmPIP2;4	0.56	0.83	0.17	0.38	0.20
ZmPIP2;5	0.80	0.73	0.32	0.64	0.59
ZmPIP2;6	1.13	0.96	0.19	0.70	0.79
ZmPIP2;7a	–	–	–	–	–

^aGene not expressed.