OsGL1-3 is Involved in Cuticular Wax Biosynthesis and Tolerance to Water Deficit in Rice

Cuticular wax covers aerial organs of plants and functions as the outermost barrier against non-stomatal water loss. We reported here the functional characterization of the Glossy1(GL1)-homologous gene OsGL1-3 in rice using overexpression and RNAi transgenic rice plants. OsGL1-3 gene was ubiquitously expressed at different level in rice plants except root and its expression was up-regulated under ABA and PEG treatments. The transient expression of OsGL1-3–GFP fusion protein indicated that OsGL1-3 is mainly localized in the plasma membrane. Compared to the wild type, overexpression rice plants exhibited stunted growth, more wax crystallization on leaf surface, and significantly increased total cuticular wax load due to the prominent changes of C₃₀–C₃₂ aldehydes and C₃₀ primary alcohols. While the RNAi knockdown mutant of OsGL1-3 exhibited no significant difference in plant height, but less wax crystallization and decreased total cuticular wax accumulation on leaf surface. All these evidences, together with the effects of OsGL1-3 on the expression of some wax synthesis related genes, suggest that OsGL1-3 is involved in cuticular wax biosynthesis. Overexpression of OsGL1-3 decreased chlorophyll leaching and water loss rate whereas increased tolerance to water deficit at both seedling and late-tillering stages, suggesting an important role of OsGL1-3 in drought tolerance.     

Novel<Emphasis Type="Italic"> eceriferum</Emphasis> mutants in<Emphasis Type="Italic"> Arabidopsis thaliana</Emphasis>

We conducted a novel non-visual screen for cuticular wax mutants in Arabidopsis thaliana (L.) Heynh. Using gas chromatography we screened over 1,200 ethyl methane sulfonate (EMS)-mutagenized lines for alterations in the major A. thaliana wild-type stem cuticular chemicals. Five lines showed distinct differences from the wild type and were further analyzed by gas chromatography and scanning electron microscopy. The five mutants were mapped to specific chromosome locations and tested for allelism with other wax mutant loci mapping to the same region. Toward this end, the mapping of the cuticular wax (cer) mutants cer10 to cer20 was conducted to allow more efficient allelism tests with newly identified lines. From these five lines, we have identified three mutants defining novel genes that have been designated CER22, CER23, and CER24. Detailed stem and leaf chemistry has allowed us to place these novel mutants in specific steps of the cuticular wax biosynthetic pathway and to make hypotheses about the function of their gene products.Abbreviations EMS Ethyl methane sulfonate - SEM Scanning electron microscopy - SSLP Simple sequence length polymorphism - WT Wild type     

Epicuticular Wax and Cuticular Resistance in Rice

High leaf cuticular resistance has been reported as a component adaptation of plants to drought prone regions, Experiments were conducted to evaluate and characterize the role of epicuticular wax as a component of cuticular resistance to water vapor loss from rice (Oryza sativa L.) leaves. This information is necessary to determine the applicability of including higher cuticular resistance in an upland rice breeding program and to evaluate potential selection methods. Diffusion porometry, electron microscopy, and gas liquid chromatography were employed. Measurement of cuticular resistance by leaf diffusive resistance porometry after stomatal closure by exposure of rice leaves to pure CO₂ for 15 min was found sufficient to induce complete stomatal closure regardless of light level, and was superior to dark acclimation for this purpose. Removal of epicuticular wax from rice leaves by chloroform dip significantly reduced the cuticular resistance. Stressed plants were observed to increase cuticular resistance, illustrating the responsive nature of this characteristic. Gas liquid chromatography (GLC) of the chloroform leaf dip proved to be an expedient method of characterizing both quantitative and qualitative differences in the epicuticular wax of rice cullivars. The porometry and GLC techniques may be useful in selecting parents, spot checking in a pedigree program, or checking lines reaching the yield testing stage, but ate not well suited lor mass screening early generation progeny. Significant differences were found in the two rice cultivurs, ‘63–83′, an upland adapted rice from West Africa, and “IR20′, bred and selected in submerged paddy culture in ihc Philippines, by tlie above methods of characterizing cuticular resistance and epicuticular wax. These results are of ecological significance to plant breeders.     

Effects of light, CO2 and humidity on carnation growth, hyperhydration and cuticular wax development in a mist reactor

Summary Plant survival ex vitro requires functioning stomata, adequate cuticular wax composition and deposition, and normal morphological development. Light intensity, CO₂ and relative humidity were altered inside an acoustic window mist reactor to study their effects on carnation (Dianthus caryophyllus) growth, stomata development, hyperhydration and epicuticular wax content. Increasing the light intensity from 65 to 145 μmol m⁻² s⁻¹ and enrichment of the gas phase with CO₂ (1350 ppm) reduced the number of hyperhydrated plants from 75 to 25% and increased the percentage dry weight of normal (healthy) plants from 17 to 25%. Lowering the relative humidity (≈70% RH) surrounding the plants during the mist-off phase for the last 2 wk of culture reduced the number of hyperhydrated plants from 70 to 9% and also increased the percentage of dry weight of normal plants from 16 to 25%. The stomata on plants grown in conditions of high light or low humidity had smaller apertures and appeared sunken when compared to stomata from plants grown in low light and high relative humidity. The epicuticular wax profiles of plants from the greenhouse or Magenta boxes showed a distinct shift in wax compounds with developmental age, plant type (hyperhydrated or normal), and type of box that was used (vented or not). In addition, very different wax profiles were observed from plants grown in reactors with altered CO₂ and light intensities.     

The role of cuticle and epidermal cell wall in resistance of rapeseed and mustard to Rhizoctonia solani

A study was conducted to determine whether the cuticles in two genera of the family Cruciferae are effective barriers to infection by Rhizoctonia solani, and whether differences in cuticle and epidermal cell wall thickness and morphology of epicuticular wax exist between resistant and susceptible cultivars. As Canola/rapeseed (Brassica napus) and mustard (Sinapis alba) plants develop from 1 to 3 weeks of age, they become increasingly resistant to R. solani AG2-1 seedling root rot. Seven-day-old seedlings of S. alba cultivars are invariably more resistant than B. napus cultivars. Brassica napus cultivars do not show an obvious cuticle layer at 1 week but at 3 weeks the presence of a cuticle is seen through autofluorescence with a concomitant increase in resistance to R. solani. Removal of the cuticle from 3-week-old hypocotyls by chloroform treatment results in a decrease in cuticular autofluorescence and a significant increase in disease severity in both resistant and susceptible cultivars. Three-week-old plants of S. alba have a much lower percent disease rating and a significantly (p=0.05) thicker cuticle layer than similar-age plants of B. napus. The results suggest that the cuticle plays an important role in the resistance of S. alba and older plants of B. napus to infection by R. solani.     

Genome-wide analysis of intronless genes in rice and <Emphasis Type="Italic">Arabidopsis</Emphasis>

Intronless genes, a characteristic feature of prokaryotes, constitute a significant portion of the eukaryotic genomes. Our analysis revealed the presence of 11,109 (19.9%) and 5,846 (21.7%) intronless genes in rice and Arabidopsis genomes, respectively, belonging to different cellular role and gene ontology categories. The distribution and conservation of rice and Arabidopsis intronless genes among different taxonomic groups have been analyzed. A total of 301 and 296 intronless genes from rice and Arabidopsis, respectively, are conserved among organisms representing the three major domains of life, i.e., archaea, bacteria, and eukaryotes. These evolutionarily conserved proteins are predicted to be involved in housekeeping cellular functions. Interestingly, among the 68% of rice and 77% of Arabidopsis intronless genes present only in eukaryotic genomes, approximately 51% and 57% genes have orthologs only in plants, and thus may represent the plant-specific genes. Furthermore, 831 and 144 intronless genes of rice and Arabidopsis, respectively, referred to as ORFans, do not exhibit homology to any of the genes in the database and may perform species-specific functions. These data can serve as a resource for further comparative, evolutionary, and functional analysis of intronless genes in plants and other organisms. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Two sides of a leaf blade: <Emphasis Type="Italic">Blumeria graminis</Emphasis> needs chemical cues in cuticular waxes of <Emphasis Type="Italic">Lolium perenne</Emphasis> for germination and differentiation

Plant surface characteristics were repeatedly shown to play a pivotal role in plant–pathogen interactions. The abaxial leaf surface of perennial ryegrass (Lolium perenne) is extremely glossy and wettable compared to the glaucous and more hydrophobic adaxial surface. Earlier investigations have demonstrated that the abaxial leaf surface was rarely infected by powdery mildew (Blumeria graminis), even when the adaxial surface was densely colonized. This led to the assumption that components of the abaxial epicuticular leaf wax might contribute to the observed impairment of growth and development of B. graminis conidia on abaxial surfaces of L. perenne. To re-assess this hypothesis, we analyzed abundance and chemical composition of L. perenne ab- and adaxial epicuticular wax fractions. While the adaxial epicuticular waxes were dominated by primary alcohols and esters, the abaxial fraction was mainly composed of n-alkanes and aldehydes. However, the major germination and differentiation inducing compound, the C₂₆-aldehyde n-hexacosanal, was not present in the abaxial epicuticular waxes. Spiking of isolated abaxial epicuticular Lolium waxes with synthetically produced n-hexacosanal allowed reconstituting germination and differentiation rates of B. graminis in an in vitro germination assay using wax-coated glass slides. Hence, the absence of the C₂₆-aldehyde from the abaxial surface in combination with a distinctly reduced surface hydrophobicity appears to be primarily responsible for the failure of normal germling development of B. graminis on the abaxial leaf surfaces of L. perenne.     

QTLs linked to leaf epicuticular wax,physio-morphological and plant production traits under drought stress in rice (<Emphasis Type="Italic">Oryza sativa</Emphasis> L.)

Drought stress is the major constraint to rice (Oryza sativa L.) production and yield stability in rainfed ecosystems. Identifying genomic regions contributing to drought resistance will help to develop rice cultivars suitable for rainfed regions through marker-assisted breeding. Quantitative trait loci (QTLs) linked to leaf epicuticular wax, physio-morphological and plant production traits under water stress and irrigated conditions were mapped in a doubled haploid (DH) line population from the cross CT9993-5-10-1-M/IR62266-42-6-2. The DH lines were subjected to water stress during anthesis. The DH lines showed significant variation for epicuticular wax (EW), physio-morphological and plant production traits under stress and irrigated conditions. A total of 19 QTLs were identified for the various traits under drought stress and irrigated conditions in the field, which individually explained 9.6%–65.6% of the phenotypic variation. A region EM15_10-ME8_4-R1394A-G2132 on chromosome 8 was identified for leaf EW and rate of water loss i.e., time taken to reach 70% RWC from excised leaves in rice lines subjected to drought stress. A large effect QTL (65.6%) was detected on chromosome 2 for harvest index under stress. QTLs identified for EW, rate of water loss from excised leaves and harvest index under stress in this study co-located with QTLs linked to shoot and root-related drought resistance traits in these rice lines and might be useful for rainfed rice improvement.     

Ontogenetic variation in chemical and physical characteristics of adaxial apple leaf surfaces

The reaction of plants to environmental factors often varies with developmental stage. It was hypothesized, that also the cuticle, the outer surface layer of plants is modified during ontogenesis. Apple plantlets, cv. Golden Delicious, were grown under controlled conditions avoiding biotic and abiotic stress factors. The cuticular wax surface of adaxial apple leaves was analyzed for its chemical composition as well as for its micromorphology and hydrophobicity just after unfolding of leaves ending in the seventh leaf insertion. The outer surface of apple leaves was formed by a thin amorphous layer of epicuticular waxes. Epidermal cells of young leaves exhibited a distinctive curvature of the periclinal cell walls resulting in an undulated surface of the cuticle including pronounced lamellae, with the highest density at the centre of cells. As epidermal cells expanded during ontogenesis, the upper surface showed only minor surface sculpturing and a decrease in lamellae. With increasing leaf age the hydrophobicity of adaxial leaf side decreased significantly indicated by a decrease in contact angle. Extracted from plants, the amount of apolar cuticular wax per area unit ranged from only 0.9 microgcm(-2) for the oldest studied leaf to 1.5 microgcm(-2) for the youngest studied leaf. Differences in the total amount of cuticular waxes per leaf were not significant for older leaves. For young leaves, triterpenes (ursolic acid and oleanolic acid), esters and alcohols were the main wax components. During ontogenesis, the proportion of triterpenes in total mass of apolar waxes decreased from 32% (leaf 1) to 13% (leaf 7); absolute amounts decreased by more than 50%. The proportion of wax alcohols and esters, and alkanes to a lesser degree, increased with leaf age, whereas the proportion of acids decreased. The epicuticular wax layer also contained alpha-tocopherol described for the first time to be present also in the epicuticular wax. The modifications in the chemical composition of cuticular waxes are discussed in relation to the varying physical characteristics of the cuticle during ontogenesis of apple leaves.     

Studies on stomatal function, epicuticular wax and stem-root transition region of polyethylene glycol-treated and nontreatedin vitro grape plantlets

Summary Scanning electron microscopy, light microscopy, and gravimetric analysis was used to evaluate stomatal function, epicuticular wax, and the stem-root transition region of grape (Vitis sp. ‘Valiant’) plantlets grownin vitro, polyethylene glycoltreatedin vitro, and greenhouse-grown plants. Scanning electron microscopic studies of leaf surfaces ofin vitro-grown plants showed widely open stomata as compared to leaf stomata of polyethylene glycol-treatedin vitro-cultured and greenhouse-grown plants. Ultrastructurally, leaf epicuticular wax ofin vitro plants was less dense than in their polyethylene-treated and greenhouse counterparts. Quantitatively,in vitro-grown plants had reduced epicuticular was as compared to polyethylene glycol-treated and greenhouse-grown plants. Light microscopic studies showed no obvious differences in the vascular connections in the stem-root transition region ofin vitro-cultured, polyethylene glycol-treatedin vitro-cultured, and greenhouse-grown plants. It is therefore likely that the rapid wilting and desiccation observed after transplantingin vitro grape plantlets is due to their defective stomatal function and reduced epicuticular wax and may not be due to poor water transport associated with vascular connection.     

<Emphasis Type="Italic">OsMADS22</Emphasis>, an <Emphasis Type="Italic">STMADS11</Emphasis>-like MADS-box gene of rice,is expressed in non-vegetative tissues and its ectopic expression induces spikelet meristem indeterminacy

We report the cDNA sequence and gene expression patterns of OsMADS22, a novel member of the STMADS11-like family of MADS-box genes, from rice. In contrast to previously reported STMADS11-like genes, whose expression is detected in vegetative tissues, OsMADS22 is mainly expressed during embryogenesis and flower development. In situ hybridization analysis revealed that OsMADS22 expression is localized in the L1 layer of embryos and in developing stamen primordia. Ectopic expression of OsMADS22 in transgenic rice plants resulted in aberrant floral morphogenesis, characterized by a disorganized palea, an elongated glume, and a two-floret spikelet. The results are discussed in terms of rice spikelet development and a novel non-vegetative role for a STMADS11-like gene.     

Conservation and Diversification of <Emphasis Type="Italic">SCARECROW</Emphasis> in Maize

The SCARECROW (SCR) gene in Arabidopsis is required for asymmetric cell divisions responsible for ground tissue formation in the root and shoot. Previously, we reported that Zea mays SCARECROW (ZmSCR) is the likely maize ortholog of SCR. Here we describe conserved and divergent aspects of ZmSCR. Its ability to complement the Arabidopsis scr mutant phenotype suggests conservation of function, yet its expression pattern during embryogenesis and in the shoot system indicates divergence. ZmSCR expression was detected early during embryogenesis and localized to the endodermal lineage in the root, showing a gradual regionalization of expression. Expression of ZmSCR appeared to be analogous to that of SCR during leaf formation. However, its absence from the maize shoot meristem and its early expression pattern during embryogenesis suggest a diversification of ZmSCR in the patterning processes in maize. To further investigate the evolutionary relationship of SCR and ZmSCR, we performed a phylogenetic analysis using Arabidopsis, rice and maize SCARECROW-LIKE genes (SCLs). We found SCL23 to be the most closely related to SCR in both eudicots and monocots, suggesting that a gene duplication resulting in SCR and SCL23 predates the divergence of dicots and monocots. Electronic supplementary material Electronic supplementary material is available for this article at and accessible for authorised users.     

A subset of <Emphasis Type="Italic">OsSERK</Emphasis> genes,including <Emphasis Type="Italic">OsBAK1</Emphasis>, affects normal growth and leaf development of rice

Since the identification of BRI1-Associated receptor Kinase 1 (BAK1), a member of the Somatic Embryogenesis Receptor Kinase (SERK) family, the dual functions of BAK1 in BR signaling and innate immunity in Arabidopsis have attracted considerable attention as clues for understanding developmental processes that must be balanced between growth and defense over the life of plants. Here, we extended our research to study cellular functions of OsSERKs in rice. As it was difficult to identify an authentic ortholog of AtBAK1 in rice, we generated transgenic rice in which the expression of multiple OsSERK genes, including OsBAK1, was reduced by OsBAK1 RNA interference. Resulting transgenic rice showed reduced levels of Os-BAK1 and decreased sensitivity to BL, leading to semidwarfism in overall growth. Moreover, they resulted in abnormal growth patterns, especially in leaf development. Most of the OsBAK1RNAi transgenic rice plants were defective in the development of bulliform cells in the leaf epidermal layer. They also showed increased expression level of pathogenesis-related gene and enhanced susceptibility to a rice blast-causing fungal pathogen, Magnaporthe oryzae. These results indicate that OsSERK genes, such as OsBAK1, play versatile roles in rice growth and development.     

<Emphasis Type="Italic">FLEXIBLE CULM 1</Emphasis> encoding a cinnamyl-alcohol dehydrogenase controls culm mechanical strength in rice

Culm mechanical strength is an important agronomic trait in crop breeding. To understand the molecular mechanisms that control culm mechanical strength, we identified a flexible culm1 (fc1) mutant by screening a rice T-DNA insertion mutant library. This mutant exhibited an abnormal development phenotype, including late heading time, semi-dwarf habit, and flexible culm. In this study, we cloned the FLEXIBLE CULM1 (FC1) gene in rice using a T-DNA tagging approach. FC1 encodes a cinnamyl-alcohol dehydrogenase and is mainly expressed in the sclerenchyma cells of the secondary cell wall and vascular bundle region. In these types of cells, a deficiency of FC1 in the fc1 mutant caused a reduction in cell wall thickness, as well as a decrease in lignin. Extracts from the first internodes and panicles of the fc1 plants exhibited drastically reduced cinnamyl-alcohol dehydrogenase activity. Further histological and biochemical analyses revealed that the p-hydroxyphenyl and guaiacyl monomers in fc1 cell wall were reduced greatly. Our results indicated that FC1 plays an important role in the biosynthesis of lignin and the control of culm strength in rice. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Regulation of the <Emphasis Type="Italic">cellulose synthase-like</Emphasis> gene family by light in the maize mesocotyl

The cellulose synthase-like (ZmCSL) gene family of maize was annotated and its expression studied in the maize mesocotyl. A total of 28 full-length CSL genes and another 13 partial sequences were annotated; four are predicted to be pseudogenes. Maize has all of the CSL subfamilies that are present in rice, but the CSLC subfamily is expanded from 6 in rice to 12 in maize, and the CSLH subfamily might be reduced from 3 to 1. Unlike rice, maize has a gene in the CSLG subfamily, based on its sequence similarity to two genes annotated as CSLG in poplar. Light regulation of glycan synthase enzyme activities and CSL gene expression were analyzed in the mesocotyl. A Golgi-localized glucan synthase activity is reduced by ~50% 12 h after exposure to light. β-1,4-Mannan synthase activity is reduced even more strongly (>85%), whereas β-1,4-xylan synthase, callose synthase, and latent IDPase activity respond only slightly, if at all, to light. At least 17 of the CSL genes (42%) are expressed in the mesocotyl, of which four are up-regulated at least twofold, seven are down-regulated at least twofold, and six are not affected by light. The results contribute to our understanding of the structure of the CSL gene family in an important food and biofuel plant, show that a large percentage of the CSL genes are expressed in the specialized tissues of the mesocotyl, and demonstrate that members of the CSL gene family are differentially subject to photobiological regulation. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Gibberellin production and plant growth promotion by a newly isolated strain of <Emphasis Type="Italic">Gliomastix murorum</Emphasis>

Endophytic fungi are known to play a vital role in the growth and development of their host plants. We isolated eleven endophytic fungi from the roots of sand-dune plant Elymus mollis and their growth-promoting ability was studied on waito-c rice and Atriplex gemelinii. We found that eight fungal isolates promoted growth of both plants. Fungal isolate EM-7-1 induced maximum growth promotion in waito-c rice (9.25 cm) and Atriplex gemelinii (3.1 cm), which was higher than wild-type Gibberella fujikuroi. Gibberellin analysis of EM-7-1 culture filtrate showed the presence of bioactive gibberellins GA₁ (0.32 ng/ml), GA₃ (5.76 ng/ml), GA₄ (0.82 ng/ml) and GA₇: (0.1 ng/ml) along with physiologically inactive GA₅ (0.59 ng/ml), GA₉ (5.38 ng/ml), GA₂₀ (0.25 ng/ml) and GA₂₄ (2.03 ng/ml). The fungal isolate EM-7-1 was identified as new strain of Gliomastix murorum (G. murorum KACC43902) with 99% sequence homology. This study reports the plant growth-promoting ability of genus Gliomastix and the presence of GA₅ in the culture filtrate of fungi for the first time. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

The <Emphasis Type="Italic">ABI2</Emphasis>-dependent abscisic acid signalling controls HrpN-induced drought tolerance in <Emphasis Type="Italic">Arabidopsis</Emphasis>

HrpN, a protein produced by the plant pathogenic bacterium Erwinia amylovora, has been shown to stimulate plant growth and resistance to pathogens and insects. Here we report that HrpN activates abscisic acid (ABA) signalling to induce drought tolerance (DT) in Arabidopsis thaliana L. plants grown with water stress. Spraying wild-type plants with HrpN-promoted stomatal closure decreased leaf transpiration rate, increased moisture and proline levels in leaves, and alleviated extents of damage to cell membranes and plant drought symptoms caused by water deficiency. In plants treated with HrpN, ABA levels increased; expression of several ABA-signalling regulatory genes and the important effector gene rd29B was induced or enhanced. Induced expression of rd29B, promotion of stomatal closure, and reduction in drought severity were observed in the abi1-1 mutant, which has a defect in the phosphatase ABI1, after HrpN was applied. In contrast, HrpN failed to induce these responses in the abi2-1 mutant, which is impaired in the phosphatase ABI2. Inhibiting wild-type plants to synthesize ABA eliminated the role of HrpN in promoting stomatal closure and reducing drought severity. Moreover, resistance to Pseudomonas syringae developed in abi2-1 as in wild-type plants following treatment with HrpN. Thus, an ABI2-dependent ABA signalling pathway is responsible for the induction of DT but does not affect pathogen defence under the circumstances of this study.Hong-Ping Dong and Haiqin Yu contributed equally to this study and are regarded as joint first authors.     

Conservation of the E-function for Floral Organ Identity in Rice Revealed by the Analysis of Tissue Culture-induced Loss-of-Function Mutants of the <Emphasis Type="Italic">OsMADS1</Emphasis> Gene

Rapid progress in studies on flower development has resulted in refining the classical ‘ABC model’ into a new ‘ABCDE model’ to explain properly the regulation of floral organ identity. Conservation of E-function for flower organ identity among the dicotyledonous (dicot) plants has been revealed. However, its conservation in monocotyledonous (monocot) plants remains largely unknown. Here, we show the conservation of E-function in rice (Oryza sativaL.) by characterizing tissue culture-induced mutants of two MADS-box genes, OsMADS1and OsMADS5, which form a subclade within the well-supported clade of SEP-genes (E-function) phylogeny. Severe loss-of-function mutations of OsMADS1cause complete homeotic conversion of organs (lodicules, stamens, and carpels) of three inner whorls into lemma- and palea-like structures. Such basic deformed structure is reiterated along with the pedicel at the center of the same floret, indicating the loss of determinacy of the flower meristem. These phenotypes resemble the phenotypes caused by mutations of the dicot E-class genes, such as the Arabidopsis SEP123(SEPALLATA1/2/3) and the petunia FBP2(Floral Binding Protein 2), suggesting that OsMADS1play a very similar role in rice to that of defined E-class genes in dicot plants. In case of the loss-of-function mutation of OsMADS5, no defect in either panicles or vegetative organs was observed. These results demonstrate that OsMADS1clearly possesses E-function, and so, E-function is fundamentally conserved between dicot plants and rice, a monocot model plant.