JIA-2018-09

1938 HAN Jiao et al. Journal of Integrative Agriculture 2018, 17(9): 1932–1945 shoots are higher than those in the roots under phosphorus deficiency. 3.3. Overexpression of the McPht gene referred to an accommodation of the transgenic rice to phosphorus deficiency To functionally evaluate the McPht gene in the transgenic rice in response to phosphorus deficiency, both the transgenic rice and the wild type were continuously cultured by the pots containing 10 L of Hoagland’s nutrient solutions for 4 wk, and then rice seedlings were subjected to sufficient phosphorus supply of 12.5 mmol L –1 P 2 O 5 (Fig. 5-A) and phosphorus deficiency of 4 µmol L –1 P 2 O 5 (Fig. 5-B), and further cultured for 2 wk. Photo images showed that three transgenic rice lines revealed better growth than the wild type under sufficient phosphorus supply (Fig. 5-C) or phosphorus deficiency (Fig. 5-D). Roots scanning showed that the total root lengths of the transgenic lines were significantly higher than those of the wild type under phosphorus deficiency (Fig. 6-A), and the lateral root number of the transgenic lines OE-1 and OE-5 were higher than those of the wild type (Fig. 6-B). Conversely, the total roots length and lateral roots number of the transgenic lines were lower than those of the wild type under sufficient phosphorus supply (Fig. 6-B), and total roots projected area of the transgenic GFP Bright Chlorophyll Merged McPht+GFP GFP 10 μm 10 μm 10 μm 10 μm 10 μm 10 μm 10 μm 10 μm Fig. 3 Subcellular localization of the McPht. A, the expressed McPht::GFP fusion protein signals in the Arabidopsis mesophyll protoplasts. B, the control expressing GFP (green fluorescent protein, 16318hGFP) signals in the Arabidopsis mesophyll protoplasts. 0.0 0.5 1.0 1.5 2.0 2.5 Sufficient phosphorus Phosphorus deficiency Relative expression OE-1 OE-5 OE-7 0.0 0.5 1.0 1.5 2.0 2.5 Sufficient phosphorus Phosphorus deficiency Relative expression 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 Sufficient phosphorus Phosphorus deficiency Relative expression Shoot Root OE-1 OE-5 OE-7 A C B Fig. 4 The relative expression levels of the McPht gene under phosphorus deficiency. A, relative expressions in the roots. B, relative expressions in the shoots. C, the relative expressions of the McPht gene in the roots and shoots of Mesembryanthemum crystallinum . OE-1, OE-5, and OE-7, transgenic lines. All data represent mean±SD of three replicates.