A Critical Role of OsMADS1 in the Development of the Body of the Palea in Rice

Jianmin Wan,Wenwei Zhang,Jie Zhang,Yue Cai,Haigang Yan,Jie Jin,Xiaoman You,Liang Wang,Fei Kong,Ming Zheng,Guoxiang Wang,Ling Jiang 한국식물학회 2018 Journal of Plant Biology Vol.61 No.1

OsMADS1 plays crucial roles in the specification of floral organ identity and the determinacy of floral meristem in rice (Oryza sativa). Here we isolated a rice mutant cy15 with defective spikelets. Map-based cloning identified cy15 as a novel mutation in the C terminus of OsMADS1. Severe cy15 spikelets contained normal inner whorl organs but defective paleas, opposite to four abnormal whorls of Osmads1 flowers reported previously. In the cy15 spikelets, the size of the body was remarkably reduced in paleas, indicating a critical role of OsMADS1 in its differentiation. Moreover, the development of palea was impaired in the early stage of the cy15 spikelets. The sub-subcellular location of the mutant OsMADS1 was also affected in cy15. On the other hand, the truncated C terminus of the mutant OsMADS1 from cy15 still showed a significant transcriptional activator function. Meanwhile, though the mutant OsMADS1 retained intact M, I and K domains, its interactions with two highly homologous A-class proteins, OsMADS15 or OsMADS14, were weakened or abolished. Our data suggested that the C-terminal sequence of OsMADS1 might be required for maintaining normal morphology of spikelets in rice.

Knock-down of OsLOX by RNA interference leads to improved seed viability in rice

Suyang Bai,Niqing He,Lu Zhou,Beibei Shen,Wei Wu,Xi Liu,Ling Jiang,Jianmin Wan 한국식물학회 2015 Journal of Plant Biology Vol.58 No.5

Previous work found that lipoxygenases were key enzymes in lipid peroxidation, which causes grain deterioration during storage. In order to obtain better seed viability in rice, 10 marker-free knock-down lines were obtained in the progeny of endogenous OsLOX knock-down mutations caused by the RNAi technology. After artificial accelerated aging, there were four types of knock-down lines with higher seed viability than wild type (receptor parent). OsLOX3 knock-down line NPF1 was of special interest. In a series of experiments, including Southern blots, analysis of OsLOX3 expression, and enzymatic activity, NPF1 had better seed viability than wild-type. We also investigated the main agronomic characters of both knock-down lines and non-transgenetic wild type families. Knock-down lines were identified with generally excellent agronomic characteristics similar to the wild-type.

Genetic dissection of leaf-related traits using 156 chromosomal segment substitution lines

Xi Liu,Linglong Liu,Yinhui Xiao,Shijia Liu,Yunlu Tian,Liangming Chen,Zhiquan Wang,Ling Jiang,Zhigang Zhao,Jianmin Wan 한국식물학회 2015 Journal of Plant Biology Vol.58 No.6

A two-line super-hybrid rice (Oryza sativa L.) variety [Liangyoupei9 (LYP9)] demonstrated superiority over its both parents, viz. elite inbred lines 93-11 and Pei-ai64S (PA64S), as well as other conventional hybrids, and had long been exploited in China. However, the genetic basis of its leaf-related traits, supposed to be an important component for yield potential, remains elusive. Here, initially a set of chromosome segment substitution lines (CSSLs) was constructed, in which the genome of Pei-ai64S has been introgressed into the background of 93-11. This set was developed by marker aided selection, based on 123 polymorphic SSR markers. The introgressed chromosomal segments presented in the 156 CSSLs covered 96.46% of Pei-ai64S genome. Afterwards, the CSSLs were deployed to assess the genetic basis of leaf size (length and width) and chlorophyll content of top three leaves across five different environments. The CSSLs showed transgressive segregation for all of the traits, and significant correlations were detected among most of the traits. A total of 27 quantitative trait loci (QTL) were identified on ten chromosomes, and three QTL cluster affecting related traits were found on chromosome 3, 6, and 8, respectively. Remarkably, two key QTLs, qALW3-1 and qALW3-2, both controlling the antepenultimate leaf width, were identified in all five environments, and their effect were further validated by CSSLs harboring the two QTL alleles. Our results indicate that developing CSSLs is a powerful tool for genetic dissection of quantitative traits. Meanwhile, the QTLs controlling leaf-related traits uncovered here provide useful information for marker-assisted selection in improving the performance of leaf morphology and photosynthetic ability.

A rice White-stripe leaf3 (wsl3) mutant lacking an HD domain-containing protein affects chlorophyll biosynthesis and chloroplast development

Shaolu Zhao,Wuhua Long,Yihua Wang,Linglong Liu,Yunlong Wang,Mei Niu,Ming Zheng,Di Wang,Jianmin Wan 한국식물학회 2016 Journal of Plant Biology Vol.59 No.3

Leaf-color mutants are ideal genetic materials for understanding the mechanism of chloroplast development and chlorophyll (Chl) biosynthesis. Here we isolated and identified a new leaf-color mutant of rice, named white-stripe leaf3 (wsl3), from a 60Co-irradiated mutant pool. The wsl3 mutant displayed a visible white-stripe leaf in both young seedlings and flag leaves of mature plant. Chl content in homozygous wsl3 mutant was approximately 47% of that in the wild type. Besides, chloroplast development in the mutant was severely arrested. By a map-based cloning strategy, the wsl3 gene was finely confined to a 50.8 kb region on chromosome 1. Moreover, a 9-bp deletion was identified in the genomic region of LOC_Os01g01920, which encodes an HD (histidine and aspartic acid) domaincontaining protein. Genetic complementation confirmed that LOC_Os01g01920 could recover the lesion of wsl3 mutation. Real-time PCR analyses showed that the expression levels of WSL3 were the highest in young and flag leaves among various tissues, and most of the genes associated with Chl biosynthesis were significantly down-regulated in the wsl3 mutant. Meanwhile, in contrast to many nuclear gene-encoded phage-type RNA polymerase(s) (NEP) transcribed genes were up-regulated, most of plastid-encoded bacterialtype RNA polymerase (PEP) transcribed genes were downregulated. These results demonstrated that the WSL3 gene, as an HD domain-containing protein, is involved in chl biosynthesis and chloroplast development in rice.

Dynamic QTL Analysis of Rice Protein Content and Protein Index Using Recombinant Inbred Lines

Leina Zheng,Wenwei Zhang,Xingang Chen,Jing Ma,Weiwei Chen,Zhigang Zhao,Huqu Zhai,Jianmin Wan 한국식물학회 2011 Journal of Plant Biology Vol.54 No.5

Protein content (PC) and protein index (PI) play important roles in determining nutritional quality in rice (Oryza sativa L.). We used 71 lines derived from “Asominori/IR24” to analyze the developmental behavior of PC and PI through unconditional and conditional QTL mapping methods. In all, 10 unconditional QTLs and 6conditional QTLs for PC, and 11 unconditional QTLs and 9conditional QTLs for PI, were identified at four stages of grain filling. More were identified in the first three stages than at the final stage. Temporal patterns of gene expression for PC and PI differed over time, with several QTLs being expressed across two or three stages but many being expressed at only one stage. Some of these QTLs were closely linked with maturity QTLs reported previously. Many QTLs for PC and PI were co-localized, supporting the significant correlation found between PC and PI. Our results suggest that dynamic QTL mapping might be a valid means for revealing more genetic information about protein accumulations during seed development.

A putative plastidial adenine nucleotide transporter, BRITTLE1-3, plays an essential role in regulating chloroplast development in rice (Oryza sativa L.)

Jia Lyu,Yihua Wang,Linglong Liu,Chunming Wang,Yulong Ren,Cheng Peng,Feng Liu,Yunlong Wang,Mei Niu,Di Wang,Ming Zheng,Kunneng Zhou,Shaolu Zhao,Fuqing Wu,Haiyang Wang,Jianmin Wan 한국식물학회 2017 Journal of Plant Biology Vol.60 No.5

Differentiation from proplastids into chloroplasts isa light- and energy-dependent process. How this process isregulated is still poorly understood at the molecular level. We herein report a new putative plastidial adenine nucleotidetransporter, BRITTLE1-3 (referred to as OsBT1-3), encoded bythe rice (Oryza sativa) White Stripe Leaf 2 (WSL2) gene. Loss of OsBT1-3 function results in defective chloroplastbiogenesis, severely reduced photosynthetic efficiency, andfinally a white stripe leaf phenotype in the first four leaves. The expression levels of genes related to chlorophyllbiosynthesis and photosynthesis are drastically reduced,accompanied with over accumulation of reactive oxygenspecies (ROS) in the wsl2 mutant. OsBT1-3 is targeted tothe chloroplasts and it expresses in almost all tissues inplants, especially in young leaves. OsBT1-3 consists of 419amino acids and exhibits features of all mitochondrialcarrier proteins, including a typical transmembrane-spanningdomain and a highly conserved sequence motif designatedas the ‘mitochondrial energy transfer signatures’. Phylogeneticanalysis shows that OsBT1-3 is a putative plastidialadenine nucleotide transporter and is most closely relatedto ZmBT1-2. Together, these observations suggest that thenew putative adenine nucleotide transporter, OsBT1-3,plays an essential role in regulating chloroplast biogenesisand maintenance of ROS homeostasis during rice seedlingde-etiolation.

Green-revertible Chlorina 1 (grc1) is Required for the Biosynthesis of Chlorophyll and the Early Development of Chloroplasts in Rice

Jieqin Li,Yihua Wang,Juntao Chai,Lihua Wang,Chunming Wang,Wuhua Long,Di Wang,Yunlong Wang,Ming Zheng,Cheng Peng,Mei Niu,Jianmin Wan 한국식물학회 2013 Journal of Plant Biology Vol.56 No.5

The nuclear genes involved in chloroplast developmentand chlorophyll biosynthesis must be investigated tounderstand their functions in plant growth and development. In this study, we isolated and identified a unique leaf-colormutant of rice with a green-yellow phenotype before thefour-leaf stage and named the mutation green-revertiblechlorina 1 (grc1). The mutants had significantly lower plantheight, number of tillers, and panicle length and headedsignificantly earlier than the wild type. The levels ofchlorophylls, carotenoids, and chlorophyll precursors werealso lower. The mutation in grc1 affected chloroplastultrastructure, particularly thylakoid development. Geneticanalysis indicated that the green-yellow phenotype wascontrolled by a single recessive gene. We mapped the grc1gene to a 32.4-kb region on the long arm of chromosome 6. Through map-based cloning, we identified a 45-bp insertionin the genomic region of LOC_Os06g40080, which encodeda heme oxygenase. Expression of LOC_Os06g40080 wassignificantly down-regulated in the grc1 mutant. Subcellularlocalization showed that this heme oxygenase was localizedin the chloroplast. In summary, we isolated and identified thegene for grc1, which plays an important role in chlorophyllbiosynthesis and chloroplast development in rice.

Molecular genetic characterization of rice seed lipoxygenase 3 and assessment of its effects on seed longevity

Qizhang Long,Wenwei Zhang,Peng Wang,Wenbiao Shen,Tong Zhou,Nannan Liu,Ren Wang,Ling Jiang,Jiexue Huang,Yihua Wang,Yuqiang Liu,Jianmin Wan 한국식물학회 2013 Journal of Plant Biology Vol.56 No.4

Lipoxygenases (LOXs) are enzymes involved in lipid peroxidation. Here we reported the identification, molecular and functional characterization of the gene encoding rice (Oryza sativa L.) seed LOX3 (sLOX3). Via a map-based cloning strategy we identified Os03g0700400 as the candidate gene encoding sLOX3. Further functional complementary test and biochemical characterization of the recombinant Os03g0700400 protein verified the identification. The sLOX3 gene was highly expressed in roots, moderately in embryos and very weakly in leaves, leaf sheaths and stems. Transient expression experiment (in rice protoplasts) and subsequent laser confocal microscopic analysis demonstrated that the sLOX3 protein was localized into the cytosol. We next showed that overexpression of sLOX3 in a japonica sLOX3-normal rice cultivar, Wuyunjing 7 accelerated the decrease of seed germination ability when the seeds were routinely stored, which demonstrated that sLOX3 had a negative effect on seed longevity (storability). Meanwhile, an increased occurrence of embryo decay was observed in the same transgenic seeds, suggesting that sLOX3 might negatively affect seed longevity by facilitating colonization of particular seed pathogens. Our result forwarded the understanding of the effects of 9-LOX on rice seed longevity.

Transcriptomics Analysis Identified Candidate Genes Colocalized with Seed Dormancy QTLs in Rice (Oryza sativa L.)

Huaide Qin,Fuqing Wu,Kun Xie,Zhijun Cheng,Xiuping Guo,Xin Zhang,Jie Wang,Cailin Lei,Jiulin Wang,Long Mao,Ling Jiang,Jianmin Wan 한국식물학회 2010 Journal of Plant Biology Vol.54 No.5

Rice seed dormancy is an important trait related to the preharvest sprouting resistance of rice and is controlled by a polygene network. To identify the genes involved in this process, transcriptome analysis was applied to strong seed dormancy indica cultivar N22 and its weak dormancy mutant Q4646. The results showed that 280genes were significantly upregulated and 244 genes significantly downregulated in the seed of Q4646 as compared to N22 during 25 to 28 days after heading. These genes were mainly involved in stress response, Ccompound metabolism, plant development, DNA processing,and lipid metabolism. Some of these genes were colocalized with several reported dormancy QTLs, suggesting that they are possibly candidate genes underlying rice seed dormancy. Our work provides important clues for future effort to clone seed dormant genes in rice.

The PP6 Phosphatase Regulates ABI5 Phosphorylation and Abscisic Acid Signaling in <i>Arabidopsis</i>

Dai, Mingqiu,Xue, Qin,Mccray, Tyra,Margavage, Kathryn,Chen, Fang,Lee, Jae-Hoon,Nezames, Cynthia D.,Guo, Liquan,Terzaghi, William,Wan, Jianmin,Deng, Xing Wang,Wang, Haiyang American Society of Plant Biologists 2013 The Plant cell Vol.25 No.2

<P>This study shows that two catalytic subunits of <I>Arabidopsis</I> protein phosphatase 6 (i.e., FyPP1 and FyPP3) negatively regulate abscisic acid responses through direct interaction with and dephosphorylation of ABI5, which subsequently regulates ABI5 stability and activity, seed germination, and postgermination seedling growth in <I>Arabidopsis</I>.</P>