Chungui Lu - Academia.edu (original) (raw)

Papers by Chungui Lu

Acta Physiologiae Plantarum, 2011

The ETHYLENE-INSENSITIVE3 (EIN3)/EIN3-Like (EIL) EIN3/EILs, novel nuclear proteins, are located a... more The ETHYLENE-INSENSITIVE3 (EIN3)/EIN3-Like (EIL) EIN3/EILs, novel nuclear proteins, are located at the downstream position of the ethylene signal transduction pathway. LeEIL1, which is expressed in fruit throughout ripening, is key transcription factor in the ethylene signaling pathway in tomato. To reveal its function, the LeEIL1 gene has been transformed into and expressed in the ein2 mutant of Arabidopsis. The expression levels of the transgene in the single copy line, LeEIL1-ein2-b, were higher than those in the multiple-copy line, LeEIL1-ein2-a. The ethylene-insensitive phenotype of the ein2 mutant plants has been partially recovered by expression of LeEIL1. The florescence of LeEIL1-ein2-a and LeEIL1-ein2-b exceeded that of the ein2 mutant but was still less than that of wild type of Arabidopsis. The expression of four pathology-related genes (AtPR3, 4, AtPDF1.2 and AtGST2) has been analyzed in LeEIL1 transgenic ein2 mutant plants. The expression of AtPR3 and AtPR4, which was reduced in the ein2 mutant, was enhanced in the two transgenic Arabidopsis plants. The expression of the AtPDF1.2 gene was unaffected in the two transgenic Arabidopsis lines, the ein2 mutant and wild-type Arabidopsis plants. In addition, the expression level of AtGST2 in transgenic Arabidopsis plants was lower even than that in ein2 mutant and wild-type Arabidopsis plants.

The Plant Cell, Aug 1, 2001

A cDNA clone from tomato fruit encodes a protein with strong homology with the rab11/YPT3 class o... more A cDNA clone from tomato fruit encodes a protein with strong homology with the rab11/YPT3 class of small GTPases that is thought to be involved in the control of protein trafficking within cells. The gene, LeRab11a , showed a pattern consistent with a single copy in DNA gel blots. The corresponding mRNA was developmentally regulated during fruit ripening, and its expression was inhibited in several ripening mutants. Its reduced expression in the Never-ripe mutant indicates that it may be induced by ethylene in fruit. The ripening-induced expression in tissues that are undergoing cell wall loosening immediately suggests a possible role in trafficking of cell wall-modifying enzymes. The message also was produced in leaves and flowers but not in roots. Antisense transformation was used to generate a "mutant phenotype." Antisense fruit changed color as expected but failed to soften normally. This was accompanied by reduced levels of two cell wall hydrolases, pectinesterase and polygalacturonase. There were other phenotypic effects in the plants, including determinate growth, reduced apical dominance, branched inflorescences, abnormal floral structure, and ectopic shoots on the leaves. In some plants, ethylene production was reduced. These data suggest an alternative or additional role in exocytosis or endocytosis of homeotic proteins, hormone carriers, or receptors.

In the developing endosperm of bread wheat (Triticum aestivum), seed storage proteins are produce... more In the developing endosperm of bread wheat (Triticum aestivum), seed storage proteins are produced on the rough endoplasmic reticulum (ER) and transported to protein bodies, specialized vacuoles for the storage of protein. The functionally important gluten proteins of wheat are transported by two distinct routes to the protein bodies where they are stored: vesicles that bud directly off the ER and transport through the Golgi. However, little is known about the processing of glutenin and gliadin proteins during these steps or the possible impact on their properties. In plants, the RabD GTPases mediate ER-to-Golgi vesicle transport. Available sequence information for Rab GTPases in Arabidopsis, rice, Brachypodium and bread wheat was compiled and compared to identify wheat RabD orthologs. Partial genetic sequences were assembled using the first draft of the Chinese Spring wheat genome. A suitable candidate gene from the RabD clade (TaRabD2a) was chosen for down-regulation by RNA interference (RNAi), and an RNAi construct was used to transform wheat plants. All four available RabD genes were shown by qRT-PCR to be down-regulated in the transgenic developing endosperm. The transgenic grain was found to produce flour with significantly altered processing properties when measured by farinograph and extensograph. SE-HPLC found that a smaller proportion of HMW-GS and large proportion of LMW-GS are incorporated into the glutenin macropolymer in the transgenic dough. Lower protein content but a similar protein profile on SDS-PAGE was seen in the transgenic grain.

Plant biotechnology journal, 2010

Temperature and light are important environmental stimuli that have a profound influence on the g... more Temperature and light are important environmental stimuli that have a profound influence on the growth and development of plants. Wheat varieties can be divided on the basis of whether they require an extended period of cold to flower (vernalization). Varieties that have a requirement for vernalization also tend to be winter hardy and are able to withstand quite extreme subzero temperatures. This capacity, however, is not constitutive and plants require a period of exposure to low, non-freezing temperatures to acquire freezing tolerance: this process is referred to as cold acclimation. Cold acclimation and the acquisition of freezing tolerance require the orchestration of many different, seemingly disparate physiological and biochemical changes. These changes are, at least in part, mediated through the differential expression of many genes. Some of these genes code for effector molecules that participate directly to alleviate stress. Others code for proteins involved in signal trans...

THE PLANT CELL ONLINE, 2001

South African Journal of Botany, 2007

A newly-developed super-high-yield two-line hybrid rice (Oryza sativa L.) LiangYouPeiJiu (LYPJ) t... more A newly-developed super-high-yield two-line hybrid rice (Oryza sativa L.) LiangYouPeiJiu (LYPJ) together with its paternal line Wumang 9311 (WM9311) and maternal line Peiai 64S (PA64S) were used as experimental materials. The activities of C4 pathway photosynthetic enzymes, i.e. phosphoenolpyruvatecarboxylase (PEPcase), NADP-malic enzyme (NADP-ME), NADP-malate dehydrogenase (NADP-MDH), pyruvate phosphate dikinase (PPDK) and the key C3 pathway enzyme–ribulose-1,5-bisphosphate carboxylase (RuBPcase), as well

Proceedings of the Royal Society B: Biological Sciences, 2005

Nitrogen is the major determinant of crop yield and quality and the precise management of nitroge... more Nitrogen is the major determinant of crop yield and quality and the precise management of nitrogen fertilizer is an important issue for farmers and environmentalists. Despite this, little is known at the level of gene expression about the response of field crops to different amounts and forms of nitrogen fertilizer. Here we use expressed sequence tag (EST)-based wheat microarrays in combination with the oldest continuously running agricultural experiment in the world to show that gene expression is significantly influenced by the amount and form of nitrogenous fertilizer. In the Broadbalk winter wheat experiment at Rothamsted in the United Kingdom and at three other diverse test sites, we show that specific genes have surprisingly different expression levels in the grain endosperm when nitrogen is supplied either in an organic or an inorganic form. Many of the genes showing differential expression are known to participate in nitrogen metabolism and storage protein synthesis. However, others are of unknown function and therefore represent new leads for future investigation. Our observations show that specific gene expression is diagnostic for use of organic sources of nitrogen fertilizer and may therefore have useful applications in defining the differences between organically and conventionally grown wheat. [The sequences reported in this paper have been deposited in the GenBank database (accession nos. AL 208216-AL 831324).]

Planta, 2002

The contents of single plant cells can be sampled using glass microcapillaries. By combining such... more The contents of single plant cells can be sampled using glass microcapillaries. By combining such single-cell sampling with reverse transcription-polymerase chain reaction (RT-PCR), transcripts of individual genes can be identified and, in principle, quantified. This provides a valuable technique for the analysis and quantification of the intercellular distribution of gene expression in complex tissues. In a proof-of-principle study, the cellular locations of the transcripts of the eight isoforms of actin ( ACT) expressed in Arabidopsis thaliana (L.) Heynh. were analyzed. Cell sap was extracted from epidermal and mesophyll cells of leaves of 3- to 4-week-old plants. Single-cell (SC)-RT-PCR was used to amplify the actin transcripts using specific primer pairs for ACT1, 2, 3, 4, 7, 8, 11 and 12. Only ACT2 and ACT8 were found in epidermal and in mesophyll cells. In individual trichomes, in addition to ACT2 and ACT8, ACT7 and ACT11 transcripts were detectable. By employing the already well-characterized actin system we demonstrate the practicality and power of SC-RT-PCR as a technique for analyzing gene expression at the ultimate level of resolution, the single cell.

Plant, Cell and Environment, 2003

Thermotolerance of photosynthesis in salt-adapted Atriplex centralasiatica plants (100-400 m M Na... more Thermotolerance of photosynthesis in salt-adapted Atriplex centralasiatica plants (100-400 m M NaCl) was evaluated in this study after detached leaves and whole plants were exposed to high temperature stress (30-48 ∞ ∞ ∞ ∞ C) either in the dark or under high light (1200 mol m ----2 s ----1

PLANT PHYSIOLOGY, 2013

Carotenoids represent some of the most important secondary metabolites in the human diet, and tom... more Carotenoids represent some of the most important secondary metabolites in the human diet, and tomato (Solanum lycopersicum) is a rich source of these health-promoting compounds. In this work, a novel and fruit-related regulator of pigment accumulation in tomato has been identified by artificial neural network inference analysis and its function validated in transgenic plants. A tomato fruit gene regulatory network was generated using artificial neural network inference analysis and transcription factor gene expression profiles derived from fruits sampled at various points during development and ripening. One of the transcription factor gene expression profiles with a sequence related to an Arabidopsis (Arabidopsis thaliana) ARABIDOPSIS PSEUDO RESPONSE REGULATOR2-LIKE gene (APRR2-Like) was up-regulated at the breaker stage in wild-type tomato fruits and, when overexpressed in transgenic lines, increased plastid number, area, and pigment content, enhancing the levels of chlorophyll in immature unripe fruits and carotenoids in red ripe fruits. Analysis of the transcriptome of transgenic lines overexpressing the tomato APPR2-Like gene revealed up-regulation of several ripening-related genes in the overexpression lines, providing a link between the expression of this tomato gene and the ripening process. A putative ortholog of the tomato APPR2-Like gene in sweet pepper (Capsicum annuum) was associated with pigment accumulation in fruit tissues. We conclude that the function of this gene is conserved across taxa and that it encodes a protein that has an important role in ripening.

PLANT PHYSIOLOGY, 2002

We describe a highly efficient two-step single-cell reverse transcriptase-polymerase chain reacti... more We describe a highly efficient two-step single-cell reverse transcriptase-polymerase chain reaction technique for analyzing gene expression at the single-cell level. Good reproducibility and a linear dose response indicated that the technique has high specificity and sensitivity for detection and quantification of rare RNA. Actin could be used as an internal standard. The expression of message for Rubisco small subunit (RbcS), chlorophyll a/b-binding protein (Cab), sucrose (Suc):fructan-6fructosyl transferase (6-SFT), and Actin were measured in individual photosynthetic cells of the barley (Hordeum vulgare) leaf. Only Actin was found in the non-photosynthetic epidermal cells. Cab, RbcS, and 6-SFT genes were expressed at a low level in mesophyll and parenchymatous bundle sheath (BS) cells when sampled from plants held in dark for 40 h. Expression increased considerably after illumination. The amount of 6-SFT, Cab, and RbcS transcript increased more in mesophyll cells than in the parenchymatous BS cells. The difference may be caused by different chloroplast structure and posttranscriptional control in mesophyll and BS cells. When similar single-cell samples were assayed for Suc, glucose, and fructan, there was high correlation between 6-SFT gene expression and Suc and glucose concentrations. This is consistent with Suc concentration being the trigger for transcription. Together with earlier demonstrations that the mesophyll cells have a higher sugar threshold for fructan polymerization, our data may indicate separate control of transcription and enzyme activity. Values for the sugar concentrations of the individual cell types are reported.

Plant Cell Reports, 2012

A novel member of the AP2/ERF transcription factor family, SlERF5, was identified from a tomato m... more A novel member of the AP2/ERF transcription factor family, SlERF5, was identified from a tomato mature leaf cDNA library screen. The complete DNA sequence of SlERF5 encodes a putative 244-amino acid DNA-binding protein which most likely acts as a transcriptional regulator and is a member of the ethylene responsive factor (ERF) superfamily. Analysis of the deduced SlERF5 protein sequence showed that it contained an ERF domain and belonged to the class III group of ERFs proteins. Expression of SlERF5 was induced by abiotic stress, such as high salinity, drought, flooding, wounding and cold temperatures.

Plant Breeding, 2004

To improve the width of compatibility for overcoming various sterilities in inter-subspecific hyb... more To improve the width of compatibility for overcoming various sterilities in inter-subspecific hybrid rice, some elite lines combining several sterility-neutral genes were developed and the effects on mitigating various hybrid sterilities were tested. From Akihikari// IR36/Dular, neutral genes at ga11 and six sterility loci, S5, S7, S8, S9, S15 and S16, were combined and elite lines were obtained in their successive progeny. Four of the lines tested were confirmed to combine the neutral alleles S5-n, S7-n, S8-n, S9-n, S15-n and S16-n at the sterility loci and, among them, two harboured an additional gamete abortion-neutral allele, ga11-n. F 1 s, which used the lines and various testers as parents, mitigated the spikelet sterilities by six sterility loci and gamete abortion by a gametophyte gene, ga11. These lines could be selectively used as parents or donors to increase the width of compatibility of rice varieties for improving fertility in inter-subspecific hybrid rice breeding.

Plant Biotechnology Journal, 2004

Grain development, germination and plant development under abiotic stresses are areas of biology ... more Grain development, germination and plant development under abiotic stresses are areas of biology that are of considerable interest to the cereal community. Within the Investigating Gene Function programme we have produced the resources required to investigate alterations in the transcriptome of hexaploid wheat during these developmental processes. We have single pass sequenced the cDNAs of between 700 and 1300 randomly picked clones from each of 35 cDNA libraries representing highly specific stages of grain and plant development. Annotated sequencing results have been stored in a publicly accessible, online database at http:// www.cerealsdb.uk.net. Each of the tissue stages used has also been photographed in detail, resulting in a collection of high-quality micrograph images detailing wheat grain development. These images have been collated and annotated in order to produce a web site focused on wheat development (http:// www.wheatbp.net / ). We have also produced high-density microarrays of a publicly available wheat unigene set based on the 35 cDNA libraries and have completed a number of microarray experiments which validate their quality.

Photosynthetica, 2004

We investigated responses of chloroplasts from flag leaves of a newly-developed super-high-yield ... more We investigated responses of chloroplasts from flag leaves of a newly-developed super-high-yield rice (Oryza sativa L.) hybrid LiangYouPeiJiu (LYPJ) to water stress (withholding irrigation) during the grain-filling period. In the early stage of water stress (0-6 d) only the activity of Hill reaction was inhibited, whereas activities of photophosphorylation and Ca 2+ -ATPase, and ATP content were increased and peaked in the day 6 of withholding irrigation. In the late stage of water stress (6-12 d), the activities of photosynthetic O 2 evolution, Hill reaction, photophosphorylation, and Ca 2+ -ATPase, and ATP content were significantly reduced. The membrane lipid content was sharply decreased, especially of sulfoquinovosyl-diacylglycerol (SQDG) and phosphatidylglycerol (PG). The changes in the ultrastructure of chloroplasts included mainly a decrease in number of grana and increase in number of osmiophilic granules.

Molecular Plant, 2011

Crown roots are main components of the fibrous root system and important for crops to anchor and ... more Crown roots are main components of the fibrous root system and important for crops to anchor and absorb water and nutrition. To understand the molecular mechanisms of crown root formation, we isolated a rice mutant defective in crown root emergence designated as Oscand1 (named after the Arabidopsis homologous gene AtCAND1). The defect of visible crown root in the Oscand1 mutant is the result of cessation of the G2/M cell cycle transition in the crown root meristem. Map-based cloning revealed that OsCAND1 is a homolog of Arabidopsis CAND1. During crown root primordium development, the expression of OsCAND1 is confined to the root cap after the establishment of fundamental organization. The transgenic plants harboring DR5::GUS showed that auxin signaling in crown root tip is abnormal in the mutant. Exogenous auxin application can partially rescue the defect of crown root development in Oscand1. Taken together, these data show that OsCAND1 is involved in auxin signaling to maintain the G2/M cell cycle transition in crown root meristem and, consequently, the emergence of crown root. Our findings provide new information about the molecular regulation of the emergence of crown root in rice.

Journal of Plant Research, 2007

Responses of net photosynthetic rates to intercellular CO(2) concentration (P (n)/C (i) curves) a... more Responses of net photosynthetic rates to intercellular CO(2) concentration (P (n)/C (i) curves) and photochemical characteristics were investigated in flag leaves of newly developed superhigh-yield hybrid rice (Oryza sativa L.) LiangYouPeiJiu (LYPJ) and its maternal PeiAi64S (PA64S) and paternal WuMang9311 (WM9311) lines grown in the field during the reproductive stage. The results showed that photosynthetic functions, such as the electron transport activities of photosystems and photophosphorylation, assessed in vivo from P (n)/C (i) curves under field conditions declined more or earlier than those obtained in vitro. The degradation of polypeptides of thylakoid membranes was slower than those for P (Ca=360) (light-saturated net photosynthetic rate measured at 360 mumol mol(-1)) and CE (carboxylation efficiency, obtained from the initial slope of the P (n)/C (i) curve). The initial inhibition of the PSII electron transport and oxygen-evolving activity induced by senescence occurred before the degradation of the oxygen-evolving complex. In comparison, LYPJ had intermediate photosynthetic functions in the early stage of leaf development, but greater photochemical activities in the mid and late stages. WM9311 showed a similar pattern of changes but lower values, and PA64S had higher values in the early stage but showed a faster rate of senescence than LYPJ. These findings implied that the hybrid LYPJ demonstrated intermediate photosynthetic activities between its parents in the early stage of leaf development, whereas it had higher photosynthetic activities than its parents in the mid and late stages, which may be responsible for its high yield.