Rice Male Development under Drought Stress: Phenotypic Changes and Stage- Dependent Transcriptomic Reprogramming  Yue Jin, Hongxing Yang, Zheng Wei, Hong Ma, Xiaochun Ge  Molecular Plant  Volume 6, Issue 5, Pages 1630-1645 (September 2013) DOI: 10.1093/mp/sst067 Copyright © 2013 The Authors. All rights reserved. Terms and Conditions

Figure 1 Comparison of Rice Panicle Development, Pollen Fertility, and Grain Yield Indices in the Control and Drought-Stressed Plants. (A) Soil water content during water stress treatment. (B) Rice panicles from the control (left) and drought-stressed (right) plants at the beginning of drought stress, respectively. (C) Rice panicles from the control (left) and drought-stressed (right) plants, respectively. (D, E) Primary branches of one panicle from the control (D) and drought-stressed (E) plants, respectively. (F–I) Spikelets from the control (F) and drought-stressed (G–I) plants, respectively. (F) normal spikelet; (G) type 1 spikelet; (H) type 2 spikelet; (I) type 3 spikelet. (J) Percentages of three types of spikelets in the control and stressed plants. (K–N) Pollen grains from the florets corresponding to (F), (G), (H), and (I) stained by iodine/potassium iodide, respectively. (O) Panicle length of the plants from normal growth and drought-stressed conditions, respectively. (P) Pollen fertility of (K), (L), (M), and (N). (Q–S) Spikelet fertility, 1000-kernel weight, and seed setting rate under the normal and drought conditions, respectively. Scale bar: 1 mm in (B); 3 cm in (C) and (E); 1 mm in (I); 50 μm in (M). The data were presented as means ± SE (n > 20). Error bars indicate SE. * p < 0.01; ** p < 0.005. Molecular Plant 2013 6, 1630-1645DOI: (10.1093/mp/sst067) Copyright © 2013 The Authors. All rights reserved. Terms and Conditions

Figure 2 Comparison of Anther Development in the Control and Drought-Stressed Plants. (A) Drought stress caused aberrant anther development. (a) Anther of stage 8 under normal growth conditions. (b–d) Abnormal anther development of stage 8 under drought stress. (e) Anther of stage 11 under normal conditions. (f–h) Abnormal anther development of stage 11 under drought stress. (i) Anther of stage 12 under normal growth conditions. (j–m) Abnormal anther development of stage 12 under drought stress. Red arrows indicate abnormal sites. Scale bars: 50 μm. (B) Statistical analysis of the abnormal phenotypes (n > 200). Molecular Plant 2013 6, 1630-1645DOI: (10.1093/mp/sst067) Copyright © 2013 The Authors. All rights reserved. Terms and Conditions

Figure 3 Comparison of the Starch Deposition Pattern in Anthers from the Control and Drought-Stressed Plants. (A) Anther cross-sections of different developmental stages under normal growth conditions are shown in (a)–(c) and (g)–(i) (lemma) and those under drought conditions are shown in (d)–(f) and (j)–(l) (lemma). Scale bars: 50 μm in (a)–(h), (j), and (k); 100 μm in (i) and (l). (B) Sections in (A) were stained by toluidine blue to show the developmental stages. The sections are arranged in the same order as that in (A). C, connective tissue; E, epidermis; En, endothecium; MC, meiotic cell; ML, middle layer; MMC, microspore mother cell; Msp, microspore; SG, starch granule; T, tapetum; Vb, vesicular bundle. Molecular Plant 2013 6, 1630-1645DOI: (10.1093/mp/sst067) Copyright © 2013 The Authors. All rights reserved. Terms and Conditions

Figure 4 Identification of Drought-Responsive Genes in Rice Florets. (A) Principal component analysis of rice floret samples using transcriptome data averaged from three replicates. The first two principal components (PCs) are shown. (B, C) Venn diagrams for drought-responsive genes among different stages of floral samples by the local t-test method (B) and by the local z-score cut-off method (C). Molecular Plant 2013 6, 1630-1645DOI: (10.1093/mp/sst067) Copyright © 2013 The Authors. All rights reserved. Terms and Conditions

Figure 5 Comparison of Microarray and qRT–PCR Analysis Results. Os06g0593100, coding for UDP-galactose/UDP-glucose transporter; Os05g0187100, for 6-phosphofructokinase; Os07g0206600 for hexose transporter; Os09g0526700, for UDP-galactose/UDP-glucose transporter; Os03g0752800, coding for OsMADS14; Os07g0605200, for OsMADS18; Os08g0112700, for OsMADS26; Os04g0448900, coding for zeaxanthin epoxidase; Os02g0703600, for ABA 8’-hydroxylase 1; Os09g0457100, for ABA 8’-hydroxylase 3; Os03g0167600, coding for DPW (Ortholog of Arabidopsis MS2); Os04g0543700, for a meiotic serine protease; Os03g0578900, coding for GAMYBL2; Os03g0168600, for CYP704B2; Os04g0670500, for OsCP1; Os08g0546300, for OsC4. The data are presented as means ± SE (n = 3). Molecular Plant 2013 6, 1630-1645DOI: (10.1093/mp/sst067) Copyright © 2013 The Authors. All rights reserved. Terms and Conditions

Figure 6 Comparison of Development-Regulated and Drought-Responsive Genes in 2–7-mm Rice Florets. (A) Developmentally up-regulated genes in florets of control plants and drought-stressed plants, respectively. (B) Developmentally down-regulated genes in florets of control plants and drought-stressed plants, respectively. (C) The overlap of drought-responsive genes and developmentally up-regulated genes. (D) The overlap of drought-responsive genes and developmentally down-regulated genes. Molecular Plant 2013 6, 1630-1645DOI: (10.1093/mp/sst067) Copyright © 2013 The Authors. All rights reserved. Terms and Conditions

Figure 7 The Expression Level Changes of Reproduction-Related Genes in Response to Drought. (A) Expression level of meiotic genes under normal conditions. (B) Expression-level changes of meiotic genes in response to drought in rice florets. (C) Expression-level changes of tapetum and microspore-expressing genes in response to drought in rice florets. (D) Expression-level changes of MADS genes in response to drought in rice florets. The same color in (A), (B), (C), and (D) does not indicate the same gene. Molecular Plant 2013 6, 1630-1645DOI: (10.1093/mp/sst067) Copyright © 2013 The Authors. All rights reserved. Terms and Conditions

Figure 8 Working Model of Drought Stress on Rice Male Development. Molecular Plant 2013 6, 1630-1645DOI: (10.1093/mp/sst067) Copyright © 2013 The Authors. All rights reserved. Terms and Conditions