Li R , Wang J , Li S , Zhang L , Qi C , Weeda S , Zhao B , Ren S , Guo YD .

	Figure 1. Heatmap of PIPs and TIPs expression in root, stem, flower, and root tissues of tomato plants. SlPIP2s transcript abundance in leaves, roots, stems and flowers was analyzed using qRT-PCR.The expression values were calculated using the 2–Δt method and the 18S housekeeping gene, and the average log2 values of three replicates were used to generate a heat map in cluster 3.0 software. Green represents low expression, and red denotes high expression. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article).
	Figure 2. Phylogenetic relationship of SlPIP2;1, SlPIP2;7 and SlPIP2;5 with PIP proteins. The predicted amino acid sequences of the three SlPIP2s and their corresponding sequences from other species were aligned using the ClustalW2 sequence alignment program. The phylogenetic tree was constructed using MEGA6 software.
	Figure 3. Alignment of predicted amino acid sequence of tomato aquaporins (SlPIP2;1, SlPIP2;7 and SlPIP2;5) with other aquaporins (DNAMAN). The predicted amino acid sequences of SlPIP2;1, SlPIP2;7 and SlPIP2;5 were compared with aquaporins from different sources. Transmembrane domains are shown with a dashed line below the alignment; circles indicate the NPA selectivity filter.
	Figure 4. (a–p) Subcellular localizations of SlPIP2;1, SlPIP2;7 and SlPIP2;5 in onion epidermal cells. The fusion protein SlPIP2;1–GFP (a,e,i,m), SlPIP2;7–GFP (b,f,j,n), SlPIP2;5–GFP (c,g,k,o) and GFP alone (d,h,l,p) were transiently expressed under the control of the cauliflower mosaic virus 35S promoter in onion epidermal cells.Images are dark field for green fluorescence (a–d, i–l,); merged (e–h, m–p); plasmolysed the cells with 0.8 M mannitol (i–p). PM, plasma membrane; CW, cell wall. (r–u) Tissue localization of expression of aquaporins in roots of tomato. Expression was analyzed by in situ hybridization in root. Three candidate aquaporin genes SlPIP2;7 (t) and SlPIP2;1 (u) were studied, panel (r) is the positive control and panel (s) is the negative control. EP:epidermis, C: cortex, EN: endodermis, S: stele. Bar = 400 μm.
	Figure 5. Assay on functional expression of SlPIP2;1, SlPIP2;7 and SlPIP2;5 in Xenopus oocytes.(A) Increase in relative volume of oocytes injected with SlPIP2;1, SlPIP2;7 and SlPIP2;5 cDNA after transfer to hypoosmotic medium, using water as control. (B) Pf-values of oocytes injected with SlPIP2;1, SlPIP2;7 and SlPIP2;5 cRNA, using water as the control. Pf of oocytes expressing SlPIP2;1, SlPIP2;7 and SlPIP2;5 present significant differences from negative control. Significant differences were determined by Duncan’s multiple range test (P < 0.05). Error bars indicate SD (n = 3). (C) SlPIP2;1, SlPIP2;7 and SlPIP2;5 expressing oocytes were exposed to different external (pHe) or internal (pHi) pH conditions. Pf for oocytes expressing SlPIP2s exposed to internal acidification is statistically different from itscontrol (i.e. pHi = 7.5), while treatment with pHe = 6.0 does notresult in a significant inhibition when compared with itscontrol (pHe = 7.5). Significant differences were determined by Duncan’s multiple range test (P < 0.05). Error bars indicate SD (n = 3). (D) SlPIP2;1, SlPIP2;7 and SlPIP2;5 expressing oocytes were exposed to 100 mM HgCl2 condition. Pf for oocytes expressing SlPIP2s exposed toHg result in a significant inhibition when compared with itscontrol. Significant differences were determined by Duncan’s multiple range test (P < 0.05). Error bars indicate SD (n = 3).
	Figure 6. Root hydraulic conductivity of tomato plants. (A) The relation between P to Jv of water supplied in tomato root system. (B) Hydraulic conductivity of tomato roots under normal and drought stress. Theroot hydraulic conductance was down regulated under drought treatment. Significant differences were determined by Duncan’s multiple range test (P < 0.05). Error bars indicate SD (n = 3). Drought (C) and salt (D) regulation of SlPIP2;1, SlPIP2;7 and SlPIP2;5 expression in tomato roots. Significant differences were determined by Duncan’s multiple range test (P < 0.05). Error bars indicate SD (n = 3).
	Figure 7. Growth of the wild-type and transgenic plants under normal and drought growth conditions. (A) Germination rates of the wild-type and transgenic Arabidopsis under normal conditions. Error bars indicate SD (n = 3). (B) Germination rates of the wild-type and transgenic Arabidopsis under drought conditions. Error bars indicate SD (n = 3). (C) The wild-type and transgenic Arabidopsis plants were photographed 20 days after germination on soil before drought treatment. (D) Phenotypes of wild-type and transgenic Arabidopsis plants subjected to drought stress for 10 days. (E) The wild-type and transgenic tomato plants were photographed 30 d after germination on soil before drought treatment. (F) Phenotypes of wild-type and transgenic tomato plants subjected to drought stress for 15 days. L1: Transgenic line1; L2: Transgenic line2.Confirmation of the transgenic lines. RT- PCR or real time quantitative analyses of the expression of SlPIP2;4, SlPIP2;5 or SlPIP2;7 in the wild-type plants and independent transgenic lines (L-1and L-2) in (G) two week-old whole Arabidopsis plants grown in MS medium and (H) two-week-old tomato plants grown in MS medium.
	Figure 8. Analysis of RWC and MDA in transgenic lines under drought stress. Tomato leaves were sampled from WT and transgenic lines under drought stress for 15 d to detect RWC (A) and MDA (B). Significant differences were determined by Duncan’s multiple range test (P < 0.05). Error bars indicate SD (n = 3).

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