Rice RHC Encoding a Putative Cellulase is Essential for Normal Root Hair Elongation

Moon, Sunok,Chandran, Anil Kumar Nalini,Kim, Yu-Jin,Gho, Yunshil,Hong, Woo-Jong,An, Gynheung,Lee, Chanhui,Jung, Ki-Hong Botanical Society of Korea 2019 Journal of plant biology Vol.62 No.1

RSL Class II Transcription Factors Guide the Nuclear Localization of RHL1 to Regulate Root Hair Development

Moon, Sunok,Cho, Lae-Hyeon,Kim, Yu-Jin,Gho, Yun-Shil,Jeong, Ho Young,Hong, Woo-Jong,Lee, Chanhui,Park, Hyon,Jwa, Nam‐,Soo,Dangol, Sarmina,Chen, Yafei,Park, Hayeong,Cho, Hyun-Soo,An, Gynheung,Jun American Society of Plant Biologists 2019 PLANT PHYSIOLOGY - Vol.179 No.2

<P>Root Hair Defective Six Like (RSL) Class II family proteins regulate root hair development by mediating RHL1 import into the nucleus.</P><P>Root hairs are important for absorption of nutrients and water from the rhizosphere. The Root Hair Defective-Six Like (RSL) Class II family of transcription factors is expressed preferentially in root hairs and has a conserved role in root hair development in land plants. We functionally characterized the seven members of the RSL Class II subfamily in the rice (<I>Oryza sativa</I>) genome. In root hairs, six of these genes were preferentially expressed and four were strongly expressed. Phenotypic analysis of each mutant revealed that <I>Os07g39940</I> plays a major role in root hair formation, based on observations of a short root hair phenotype in those mutants. Overexpression (OX) for each of four family members in rice resulted in an increase in the density and length of root hairs. These four members contain a transcription activation domain and are targeted to the nucleus. They interact with rice Root Hairless1 (OsRHL1), a key regulator of root hair development. When heterologously expressed in epidermal cells of <I>Nicotiana benthamiana</I> leaves, OsRHL1 was predominantly localized to the cytoplasm. When coexpressed with each of the four RSL Class II members, however, OsRLH1 was translocated to the nucleus. Transcriptome analysis using <I>Os07g39940-</I>OX plants revealed that 86 genes, including Class III peroxidases, were highly up-regulated. Furthermore, reactive oxygen species levels in the root hairs were increased in <I>Os07g39940-</I>OX plants but were drastically reduced in the <I>os07g39940</I> and <I>rhl1</I> mutants. Our results demonstrate that RSL Class II members function as essential regulators of root hair development in rice.</P>

Functional Characterization of OsRac6 Involved in Pollen Germination in Rice

Su Kyoung Lee,Woo‑Jong Hong,Eui‑Jung Kim,Sunok Moon,Yu‑Jin Kim,박순기,정기홍 한국식물학회 2023 Journal of Plant Biology Vol.66 No.5

For a successful reproduction in angiosperms, pollen germination and pollen tube growth must proceed normally. The processes are regulated by transcriptional regulation and cellular activities, in which signaling proteins are the key. Ras homolog (Rho)-type GTPases (Rops), which are known as RACs, are a group of Rho small GTP-binding proteins which evolved in plants. However, the molecular mechanisms of the rice Rac family (OsRac) genes in pollen germination are not yet understood. In this investigation, the OsRac6 gene, which is only expressed only during the pollen development stage, was identified. A functional characterization of OsRac6 using gene-edited mutants exhibits male sterility due to the disruption of pollen germination. Then, to determine downstream candidate genes modulated by the OsRac6 genes during pollen development, we performed RNA-seq analysis by comparing osrac6-1 and wild-type (WT) anthers. Subsequently, we identified 652 genes with pollen-preferential expression which were upregulated compared with the WT, and 608 genes which were downregulated. Furthermore, gene ontology (GO) enrichment and MapMan analyses show that downregulated genes are closely associated with transcription, protein ubiquitination, proteolysis, cell wall modification, cell organization, cell cycle, and calcium regulation. The results of this study will help in elucidating the molecular mechanisms of pollen germination in rice mediated by OsRac6.

Meta-expression analysis of unannotated genes in rice and approaches for network construction to suggest the probable roles

Chandran, Anil Kumar Nalini,Bhatnagar, Nikita,Yoo, Yo-Han,Moon, Sunok,Park, Sun-Ah,Hong, Woo-Jong,Kim, Beom-Gi,An, Gynheung,Jung, Ki-Hong Springer-Verlag 2018 Plant Molecular Biology Vol.96 No.1

<P>Although the genome of rice (Oryza sativa) has been sequenced, 14,365 genes are considered unannotated because they lack putative annotation information. According to the Rice Genome Annotation Project Database (http://rice.plantbiology.msu.edu/), the proportion of functionally characterized unannotated genes (0.35%) is quite limited when compared with the approximately 3.9% of annotated genes with assigned putative functions. Researchers require additional information to help them investigate the molecular mechanisms associated with those unannotated genes. To determine which of them might regulate morphological or physiological traits in the rice genome, we conducted a meta-analysis of expression data that covered a wide range of tissue/organ samples. Overall, 2020 genes showed cultivar-, tissue-, or organ-preferential patterns of expression. Representative candidates from featured groups were validated by RT-PCR, and the GUS reporter system was used to validate the expression of genes that were clustered according to their leaf or root preference. Taking a molecular and genetics approach, we examined meta-expression data and found that 127 genes were differentially expressed between japonica and indica rice cultivars. This is potentially significant for future agronomic applications. We also used a T-DNA insertional mutant and performed a co-expression network analysis of Sword shape dwarf1 (SSD1), a gene that regulates cell division. This network was refined via RT-PCR analysis. Our results suggested that SSD1 represses the expression of four genes related to the processes of DNA replication or cell division and provides insight into possible molecular mechanisms. Together, these strategies present a valuable tool for in-depth characterization of currently unannotated genes.</P>

Inverse association of improved adherence to dietary guidelines with metabolic syndrome: the Seoul Metabolic Syndrome Management program

Dongwoo Ham,YoungYun Cho,Mi-Suk Park,Yun-Sug Park,Sun-Young Kim,Hye-Min Seol,Yoo Mi Park,Sunok Woo,Hyojee Joung,Do-Sun Lim 한국영양학회 2020 Nutrition Research and Practice Vol.14 No.6

BACKGROUND/OBJECTIVES: The Seoul Metabolic Syndrome Management (SMESY) program is a 1-yr lifestyle modification program targeting metabolic syndrome (MetS) in Seoul residents. This study investigated the associations between adherence to dietary guidelines and MetS among the SMESY program participants. SUBJECTS/METHODS: Data of 54,385 participants aged 20-64 yrs who completed the SMESY program in 2015, had information on adherence to dietary guidelines, and were not medicated for diabetes, hypertension, or dyslipidemia were analyzed. Participants underwent MetS screening and completed a lifestyle questionnaire including adherence to 10 dietary guidelines before and after participation. Participants were classified according to the number of MetS risk factors at baseline (MetS group, ≥ 3; risk group, 1-2; healthy group, none). Adherence to dietary guidelines was determined from the number of “yes” responses regarding the fulfillment of each guideline on ≥ 5 days/week. Multiple logistic regression was used to evaluate associations between newly diagnosed MetS and changes in adherence to dietary guidelines. RESULTS: In the MetS group, MetS prevalence decreased after the SMESY program (men, -41.9%p; women, -48.7%p), and all risk factors were significantly improved (P < 0.0001). All groups exhibited improved adherence to all dietary guidelines after participation (P < 0.0001). In the MetS group with positively changed adherence scores, the MetS prevalence decreased by -44.1%p for men and -49.5%p for women, whereas the prevalence in those with negative changes decreased by -38.1%p for men and -48.6%p for women. In the risk group, those with positively changed adherence scores had significantly decreased odds ratios (ORs) for newly diagnosed MetS compared with those with negative changes (OR, 0.70; 95% confidence interval [CI], 0.61-0.80 for men; OR, 0.88; 95% CI, 0.79-0.99 for women). CONCLUSIONS: The SMESY program may effectively reduce the risk of MetS among adults with risk factors by improving adherence to dietary guidelines.