Endosperm-specific OsPYL8 and OsPYL9 act as positive regulators of the ABA signaling pathway in rice seed germination

2017 ◽  
Vol 44 (6) ◽  
pp. 635 ◽  
Author(s):  
Ziqiang Chen ◽  
Lan Kong ◽  
Yun Zhou ◽  
Zaijie Chen ◽  
Dagang Tian ◽  
...  

Pyrabactin resistance-like (PYL) proteins were identified as receptors of the plant hormone ABA. The PYL family consists of multiple members that are differently expressed in various tissues, exhibit distinct biochemical properties and have diverse biological functions. In the present study, we explored the expression patterns of the rice (Oryza sativa L.) OsPYL family genes and determined that OsPYL8 and OsPYL9 are specifically expressed in the endosperms. Sequence analysis and deletion experiments revealed that the OsPYL8 and OsPYL9 promoters contain multiple motifs involved in endosperm-specific expression. Transgenic rice plants overexpressing OsPYL8 or OsPYL9 showed hypersensitivity to ABA during seed germination, suggesting that both OsPYL8 and OsPYL9 act as positive regulators of the ABA signalling pathway in the seed. OsPYL8 and OsPYL9 interact with OsPP2C51 and OsPP2C68, whose expression is induced in the endosperms by ABA. Our results provided a foundation for future studies on OsPYL8- and OsPYL9-mediated ABA signalling in the rice endosperms.

2019 ◽  
Vol 21 (1) ◽  
pp. 245 ◽  
Author(s):  
Abolore Adijat Ajadi ◽  
Xiaohong Tong ◽  
Huimei Wang ◽  
Juan Zhao ◽  
Liqun Tang ◽  
...  

Cyclin-dependent kinase inhibitors known as KRPs (kip-related proteins) control the progression of plant cell cycles and modulate various plant developmental processes. However, the function of KRPs in rice remains largely unknown. In this study, two rice KRPs members, KRP1 and KRP2, were found to be predominantly expressed in developing seeds and were significantly induced by exogenous abscisic acid (ABA) and Brassinosteroid (BR) applications. Sub-cellular localization experiments showed that KRP1 was mainly localized in the nucleus of rice protoplasts. KRP1 overexpression transgenic lines (OxKRP1), krp2 single mutant (crkrp2), and krp1/krp2 double mutant (crkrp1/krp2) all exhibited significantly smaller seed width, seed length, and reduced grain weight, with impaired seed germination and retarded early seedling growth, suggesting that disturbing the normal steady state of KRP1 or KRP2 blocks seed development partly through inhibiting cell proliferation and enlargement during grain filling and seed germination. Furthermore, two cyclin-dependent protein kinases, CDKC;2 and CDKF;3, could interact with KRP1 in a yeast-two-hybrid system, indicating that KRP1 might regulate the mitosis cell cycle and endoreduplication through the two targets. In a word, this study shed novel insights into the regulatory roles of KRPs in rice seed maturation and germination.


2019 ◽  
Author(s):  
Yong Zhou ◽  
Yuan Cheng ◽  
Chunpeng Wan ◽  
Youxin Yang ◽  
Jinyin Chen

The plant DNA-binding with one finger (Dof) gene family is a class of plant-specific transcription factors that play vital roles in many biological processes and response to stresses. In the present study, a total of 36 ClDof genes were identified in the watermelon genome, which were unevenly distributed on 10 chromosomes. Phylogenetic analysis showed that the ClDof proteins could be divided into nine groups, and the members in a particular group had similar motif arrangement and exon-intron structure. We then analyzed the expression patterns of nine selected ClDof genes in eight specific tissues by qRT-PCR, and the results showed that they have tissue-specific expression patterns. We also evaluated the expression levels of the nine selected ClDof genes under salt stress and ABA treatments using qRT-PCR, and they showed differential expression under these treatments, suggesting their important roles in stress response. Taken together, our results provide a basis for future research on the biological functions of Dof genes in watermelon.


2019 ◽  
Vol 20 (22) ◽  
pp. 5709 ◽  
Author(s):  
Mohamed S. Sheteiwy ◽  
Hongbo Shao ◽  
Weicong Qi ◽  
Yousef Alhaj Hamoud ◽  
Hiba Shaghaleh ◽  
...  

This study was conducted in order to determine the effect of priming with γ-aminobutyric acid (GABA) at 0.5 mM on rice (Oryza sativa L.) seed germination under osmotic stress (OS) induced by polyethylene glycol (30 g/L PEG 6000); and salinity stress (S, 150 mM NaCl) and their combination (OS+S). Priming with GABA significantly alleviated the detrimental effects of OS, S and OS+S on seed germination and seedling growth. The photosynthetic system and water relation parameters were improved by GABA under stress. Priming treatment significantly increased the GABA content, sugars, protein, starch and glutathione reductase. GABA priming significantly reduced Na+ concentrations, proline, free radical and malonaldehyde and also significantly increased K+ concentration under the stress condition. Additionally, the activities of antioxidant enzymes, phenolic metabolism-related enzymes, detoxification-related enzymes and their transcription levels were improved by GABA priming under stress. In the GABA primed-plants, salinity stress alone resulted in an obvious increase in the expression level of Calcineurin B-like Protein-interacting protein Kinases (CIPKs) genes such as OsCIPK01, OsCIPK03, OsCIPK08 and OsCIPK15, and osmotic stress alone resulted in obvious increase in the expression of OsCIPK02, OsCIPK07 and OsCIPK09; and OS+S resulted in a significant up-regulation of OsCIPK12 and OsCIPK17. The results showed that salinity, osmotic stresses and their combination induced changes in cell ultra-morphology and cell cycle progression resulting in prolonged cell cycle development duration and inhibitory effects on rice seedlings growth. Hence, our findings suggested that the high tolerance to OS+S is closely associated with the capability of GABA priming to control the reactive oxygen species (ROS) level by inducing antioxidant enzymes, secondary metabolism and their transcription level. This knowledge provides new evidence for better understanding molecular mechanisms of GABA-regulating salinity and osmotic-combined stress tolerance during rice seed germination and development.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Zhiguo E ◽  
Chen Chen ◽  
Jinyu Yang ◽  
Hanhua Tong ◽  
Tingting Li ◽  
...  

AbstractFatty acid desaturases can catalyze saturated or unsaturated fatty acids to form a double bond at various locations in the hydrocarbon chain. In the present study, a total of 20 full-length desaturase genes were identified from rice genome. An exhaustive analysis was performed to describe their chromosomal locations, gene structures, phylogeny, cis-regulatory elements, sub-cellular localizations and expression patterns. The rice desaturase genes were distributed on ten of 12 chromosomes and phylogenetically classified into six subfamilies with the Arabidopsis counterparts, FAB2, FAD2, FAD3/7/8, FAD6, DES1 and SLD1. Among of them, 9 members were expanded via chromosomal tandem or segmental duplications. The gene structures and motif constituents were evolutionarily conserved in the same subfamilies. The majority of desaturase genes showed tissue-specific expression patterns and response to abiotic stresses and hormones based on microarray data and qRT-PCR analyses. This study will provide useful clues for functional validation of desaturase genes and contribute to produce nutritionally important fatty acids by genetic modification in rice.


2019 ◽  
Vol 17 (2) ◽  
pp. 153-160 ◽  
Author(s):  
Md. Arifur Rahman ◽  
Md. Sohanur Rahman ◽  
K.M. Mohiuddin ◽  
Md. Akhter Hossain Chowdhury ◽  
Md. Abul Khair Chowdhury

Indiscriminate discharge of industrial effluent has become a serious problem for the agro-ecological environment in most of the areas of Bangladesh. The effects of loom-dye effluents on seed germination and early seedling growth of rice (Oryza sativa L.) were investigated by conducting an experiment in the laboratory of the Department of Agricultural Chemistry of Bangladesh Agricultural University, Mymensingh. Three types of loom-dye effluents were applied in sterilized petridishes at different loading ratios. Seven treatments (i.e., T0, T1, T2, T3, T4, T5 and T6 with 0, 5, 10, 25, 50, 75 and 100% effluent, respectively) of each effluent were used following completely randomized design (CRD) and replicated three times. Subsequently, Pb, Fe, Zn, Mn and Cr accumulation were also investigated in the harvested rice seedlings. Rice seed showed a significant difference in germination percentage with varying levels of effluent application at different days after setting of germination. The decreased seed germination rate and seedling growth of rice were observed with increased concentration of loom-dye effluents. The highest germination speed (97.8%) was obtained from control whereas the lowest germination speeds were obtained from T5 of black, and T6 of both black and violet effluents. Phytotoxic effects of loom-dye effluents on germination and radical length were extreme at 100% effluent concentration having the order of black > violet > pink. The maximum radical length (6.4 cm) and plumule length (7.5 cm) were observed with T1 of pink dye effluent whereas the minimum length of radical and plumule were obtained from T6 treatment of the effluents. The highest fresh weight (39.8 mg petridish–1), dry weight (5.7 mg petridish–1) and seedling vigor index (746.7%) were also observed from T1 of pink dye effluent. The maximum uptake of Pb, Fe, Mn and Zn was 0.48, 3.81, 0.79 and 0.13 μg g−1, respectively. The uptake of Cr was below the detectable limit. Total heavy metal accumulation in rice was in the following order: Fe>Mn>Pb>Zn>Cr. Results showed that the higher concentration of loom-dye effluent showed the higher toxic effects on different parameters of germination and early seedling growth compared with the lower effluent concentrations. J. Bangladesh Agril. Univ. 17(2): 153–160, June 2019


2019 ◽  
Vol 20 (18) ◽  
pp. 4646 ◽  
Author(s):  
Keqin Li ◽  
Yuanliangzi Tian ◽  
Ya Yuan ◽  
Xiaolan Fan ◽  
Mingyao Yang ◽  
...  

Long non-coding RNAs (lncRNAs) are a class of non-coding RNAs longer than 200 nucleotides (nt). LncRNAs have high spatiotemporal specificity, and secondary structures have been preserved throughout evolution. They have been implicated in a range of biological processes and diseases and are emerging as key regulators of gene expression at the epigenetic, transcriptional, and post-transcriptional levels. Comparative analyses of lncRNA functions among multiple organisms have suggested that some of their mechanisms seem to be conserved. Transcriptome studies have found that some Drosophila lncRNAs have highly specific expression patterns in embryos, nerves, and gonads. In vivo studies of lncRNAs have revealed that dysregulated expression of lncRNAs in Drosophila may result in impaired embryo development, impaired neurological and gonadal functions, and poor stress resistance. In this review, we summarize the epigenetic, transcriptional, and post-transcriptional mechanisms of lncRNAs and mainly focus on recent insights into the transcriptome studies and biological functions of lncRNAs in Drosophila.


2020 ◽  
pp. 1450-1455
Author(s):  
Ramida Krumsri ◽  
Hisashi Kato Noguchi ◽  
Thanatsan Poonpaiboonpipat

The allelopathic effect of Sphenoclea zeylanica Gaertn., a broadleaf paddy weed that hinders rice production in Thailand, was investigated. Different parts of S. zeylanica were used to determine their inhibitory effect on seed germination, and shoot and root length of rice in a laboratory. Aqueous extracts of leaves and stems had an inhibitory effect on rice germination and seedling growth more than 50% that of control at concentrations higher than 50 g L-1, whereas all concentrations of root extracts had no effect on rice seeds. At the concentration of 100 g L-1, leaf and stem extracts completely (100%) inhibited rice seed germination. The inhibitory effect was increased with increasing concentrations. Additionally, leaf extracts contained higher total phenolics (7.36 mg GE g-1 DW) and total flavonoids (254.19 µg QE g-1 DW) than extracts of other parts. In glasshouse conditions, soil incorporation with dried whole plant residue had a significant inhibitory effect on rice emergence, seedling height, and dry weight when compared with extracted residue at an equal concentration. The decomposition of S. zeylanica in the soil was also evaluated regarding rice seedling growth. The maximum inhibition was achieved 1-3 days after the application of plant residues. At the 30th day, the inhibition disappeared, suggesting that residue decomposition in the soil has been finished. These results support that S. zeylanica has an allelopathic effect on paddy fields, which may cause a reduction in rice growth and yield.


PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0246021
Author(s):  
QingHua Li ◽  
XianTao Yu ◽  
Long Chen ◽  
Gang Zhao ◽  
ShiZhou Li ◽  
...  

Abscisic acid (ABA) is an important plant hormone that plays multiple roles in regulating growth and development as well as in stress responses in plants. The NCED gene family includes key genes involved in the process of ABA synthesis. This gene family has been found in many species; however, the function of the NCED gene family in cotton is unclear. Here, a total of 23 NCED genes (designated as GhNCED1 to GhNCED23) were identified in cotton. Phylogenetic analysis indicated that the identified NCED proteins from cotton and Arabidopsis could be classified into 4 subgroups. Conserved motif analysis revealed that the gene structure and motif distribution of proteins within each subgroup were highly conserved. qRT-PCR and ABA content analyses indicated that NCED genes exhibited stage-specific expression patterns at tissue development stages. GhNCED5, GhNCED6 and GhNCED13 expression was similar to the change in ABA content, suggesting that this gene family plays a role in ABA synthesis. These results provide a better understanding of the potential functions of GhNCED genes.


Genes ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 243 ◽  
Author(s):  
Juan Zhao ◽  
Abolore Adijat Ajadi ◽  
Yifeng Wang ◽  
Xiaohong Tong ◽  
Huimei Wang ◽  
...  

Rice seed is a pivotal reproductive organ that directly determines yield and quality. Long non-coding RNAs (lncRNAs) have been recognized as key regulators in plant development, but the roles of lncRNAs in rice seed development remain unclear. In this study, we performed a paired-end RNA sequencing in samples of rice pistils and seeds at three and seven days after pollination (DAP) respectively. A total of 540 lncRNAs were obtained, among which 482 lncRNAs had significantly different expression patterns during seed development. Results from semi-qPCR conducted on 15 randomly selected differentially expressed lncRNAs suggested high reliability of the transcriptomic data. RNA interference of TCONS_00023703, which is predominantly transcribed in developing seeds, significantly reduced grain length and thousand-grain weight. These results expanded the dataset of lncRNA in rice and enhanced our understanding of the biological functions of lncRNAs in rice seed development


Botany ◽  
2016 ◽  
Vol 94 (2) ◽  
pp. 91-101 ◽  
Author(s):  
Yongqi He ◽  
Jinping Cheng ◽  
Xiaodan Li ◽  
Peng Zeng ◽  
Bin Yang ◽  
...  

Desiccation tolerance is an important characteristic of rice seed quality during seed drying. In this study, two varieties of Oryza sativa L. subsp. japonica (Jiucaiqing and Wuyunjing 7) were used to investigate the dynamic changes in rice seeds that are associated with desiccation tolerance (germination traits produced by dried seeds), grain mass (GW), moisture content (MC), and electrical conductivity (EC) during seed development (18 to 42 days after heading (DAH)). Changes in the levels of malondialdehyde (MDA) and hydrogen peroxide (H2O2) in fresh, dry, and imbibed states, and antioxidant enzyme activity (superoxide dismutase (SOD); catalase (CAT); and glutathione reductase (GR)) in fresh and imbibed seeds were also evaluated during seed development. The results showed that seeds started to acquire desiccation tolerance at 26 DAH and reached the highest levels at 38 DAH. The increase in GW and decline in MC coincided with the acquisition of desiccation tolerance. MDA and H2O2 levels, and SOD, CAT, and GR activities in fresh and imbibed seeds rapidly decreased during the early developmental stages (18–30 DAH), and then their levels gradually stabilized (30–42 DAH). Regression analyses indicated that H2O2 levels in fresh seeds was negatively correlated with seed germination, whereas SOD activity in imbibed seeds was positively correlated with seed germination. H2O2 and SOD are, therefore, good parameters for assessing desiccation tolerance during rice seed development.


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