Somatic embryogenesis in Jatropha curcas Linn., an important biofuel plant

Jatropha curcas L. is one potential source of non-edible biofuel-producing energy crop. Its importance also lies in its medicinal properties. The species is primarily propagated through heterozygous seeds, and thus the seed oil content varies from 4 to 40%. Moreover, due to its perennial nature, seed setting requires 2 to 3 years time. The seed viability and rate of germination are low, and quality seed screening is another laborious task; thus, seed propagation alone cannot provide quality planting material for sustainable use. Somatic embryogenesis, a powerful tool of plant biotechnology for faster and quality plant production has been successfully applied to regenerate plants in Jatropha curcas for the first time. Embryogenic calli were obtained from leaf explants on MS basal medium supplemented with only 9.3 μM Kn. Induction of globular somatic embryos from 58% of the cultures was achieved on MS medium with different concentrations of 2.3–4.6 μM Kn and 0.5–4.9 μM IBA; 2.3 μM Kn and 1.0 μM IBA proved to be the most effective combination for somatic embryo induction in Jatropha curcas. Addition of 13.6 μM adenine sulphate stimulated the process of development of somatic embryos. Mature somatic embryos were converted to plantlets on half strength MS basal medium with 90% survival rate in the field condition. The whole process required 12–16 weeks of culture for completion of all steps of plant regeneration. This protocol of somatic embryogenesis in Jatropha curcas may be an ideal system for future transgenic research.     

Nocardioides panzhihuaensis sp. nov., a novel endophytic actinomycete isolated from medicinal plant Jatropha curcas L.

A novel Gram-positive, aerobic, rod-shaped and mycelia-producing bacterial strain, designated KLBMP 1050^T, was isolated from the stem of the oil-seed plant Jatropha curcas L. collected from Sichuan Province, south-west China. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that the isolate KLBMP 1050^T belonged to the genus Nocardioides, with the highest sequence similarity to Nocardioides albus KCTC 9186^T (99.38 %) and Nocardioides luteus KCTC 9575^T (99.03 %). However, the DNA–DNA relatedness of isolate KLBMP 1050^T to these two type strains were 37.5 ± 3.5 and 33 ± 2.3 %, respectively. Strain KLBMP 1050^T grew at the pH range 6–11, temperature range 10–32 °C and with 0–12 % NaCl. The physiological properties of strain KLBMP 1050^T differ from those of N. albus KCTC 9186^T and N. luteus KCTC 9575^T. The cell-wall peptidoglycan contained ll-diaminopimelic acid and MK-8(H₄) was the major respiratory quinone. The predominant cellular fatty acid of strain KLBMP 1050^T was iso-C_16:0 (23.3 %). The total DNA G+C content was 70.1 mol%. On the basis of the phenotypic, chemotaxonomic and phylogenetic data, strain KLBMP 1050^T represents a novel species of the genus Nocardioides, for which the name Nocardioides panzhihuaensis sp. nov. is proposed. The type strain is KLBMP 1050^T (= KCTC 19888^T = NBRC 108680^T).     

Production and selected fuel properties of biodiesel from promising non-edible oils: Euphorbia lathyris L., Sapium sebiferum L. and Jatropha curcas L

A comparative study on the composition, biodiesel production and fuel properties of non-edible oils from Euphorbia lathyris L. (EL), Sapium sebiferum L. (SS), and Jatropha curcas L. (JC) was conducted. Under optimal conditions, the FAME content and yield of the three oils were greater than 97.5 wt.% and 84.0%, respectively. The best biodiesel was produced from EL due to its high monounsaturation (82.66 wt.%, Cn: 1), low polyunsaturation (6.49 wt.%, Cn: 2, 3) and appropriate proportion of saturated components (8.78 wt.%, Cn: 0). Namely, EL biodiesel possessed a cetane number of 59.6, an oxidation stability of 10.4 h and a cold filter plug point of -11 °C. However, the cetane number (40.2) and oxidative stability (0.8 h) of dewaxed SS kernel oil (DSSK) biodiesel were low due to the high polyunsaturation (72.79 wt.%). In general, the results suggest that E. lathyris L. is a promising species for biodiesel feedstock.     

木本油料植物麻疯树的研究进展

近来,麻疯树(Jatropha curcas L.)因可以作为生物柴油的原料而受到广泛关注。虽然麻疯树具有含油量高且可在边际土地种植的优势,但同时存在理想品种缺乏、种植面积限制、基础研究薄弱等方面的问题。为了使常规育种和生物技术改良工作者更好地了解麻疯树的研究进展,确定日后麻疯树育种和遗传改良的方向,综述了麻疯树种质资源与遗传多样性分析、生理及对环境适应性、组学研究、油脂合成功能基因研究、育种等方面国内外的最新进展。     

Factors influencing direct shoot regeneration from mature leaves of Jatropha curcas, an important biofuel plant

In order to establish a highly efficient and sustainable regeneration system, we systematically researched the key factors affecting direct shoot regeneration from Jatropha curcas leaves that were collected from Hainan (HN1-1), Lijiang (LJ3-1), and Yuxi (YX2-12) provinces in China. The L₉(3⁴) orthogonal test of thidiazuron (TDZ), kinetin (Kn), and gibberellic acid (GA₃) were studied, and the explant type, growth age, and cultivar of leaves were subsequently investigated. Simultaneously, the combinations of plant growth regulators (PGRs) promoting shoot bud proliferation, elongation, and root establishment were examined. The results showed that the best medium for shoot bud induction was Murashige and Skoog (MS) medium supplemented with 1.0 mg/L TDZ, 0.5 mg/L Kn, and 0.5 mg/L GA₃. TDZ was the key PGR, while Kn and GA₃ played an important role in shoot bud elongation and the number of shoots per leaf disk, respectively. The induced shoot buds proliferated and readily elongated in MS medium with 0.3 mg/L 6-benzylaminopurine and 0.01 mg/L indole-3-butyric acid (IBA) and established roots in half-strength MS medium supplemented with 2.0 mg/L IBA. Using the previously described methods, the third to fifth leaves were found to be the best explant source for shoot bud induction, with a high induction rate, large shoot numbers per disk, excellent proliferation, and consistent rooting. With the use of this regeneration system, the shoot bud induction rate increased from the reported rate of 53.5% to more than 90% using different explants and cultivars, and the shoot number per leaf disk (shoot length?≥?0.5 cm) increased from 1.6 to 3.5. Thus, this optimized regeneration system will effectively promote the propagation and genetic transformation of J. curcas.     

Plant regeneration through the direct induction of shoot buds from petiole explants of Jatropha curcas: a biofuel plant

An efficient and reproducible method for the regeneration of Jatropha curcas plants has been developed. The method employed direct induction of shoot buds from petiole explants, without the formation of an intervening callus using a Murashige and Skoog (MS) medium supplemented with different concentrations of thidiazuron (TDZ). The best induction of shoot buds (58.35%) and the number of shoot buds per explant (10.10) were observed when in vitro petiole explants were placed horizontally on MS medium supplemented with 2.27 µM TDZ after 6 weeks. The induced shoot buds were transferred to MS medium containing 10 µM kinetin (Kn), 4.5 µM 6-benzyl aminopurine (BAP) and 5.5 µM α-naphthaleneacetic acid (NAA) for shoot proliferation. The proliferated shoots could be elongated on MS medium supplemented with different concentrations and combinations of BAP, indole-3-acetic acid (IAA), NAA and indole-3-butyric acid (IBA). MS medium supplemented with 2.25 µM BAP and 8.5 µM IAA was found to be the best combination for shoot elongation and 3.01–3.91 cm elongation was achieved after 6 weeks. However, significant differences in plant regeneration and shoot elongation were observed among the genotypes studied. The orientation (horizontal or vertical) and source (in vitro or in vivo) of explants also significantly influenced plant regeneration. The elongated shoots could be rooted on half-strength MS medium supplemented with 2% sucrose, different concentrations and combinations of IBA, IAA and NAA, and 0.25 mg L⁻¹ activated charcoal. Half-strength MS medium supplemented with 2% sucrose, 15 µM IBA, 5.7 µM IAA, 5.5 µM NAA and 0.25 mg L⁻¹ activated charcoal was found to be the best for promoting rooting. The rooted plants could be established in soil with more than 90% survival.     

Molecular cloning, characterization and expression of cDNA encoding translationally controlled tumor protein (TCTP) from Jatropha curcas L

A cDNA encoding translationally controlled tumor protein (TCTP) of Jatropha curcas L., JcTCTP, was isolated from an endosperm cDNA library. JcTCTP consisted of a 5?? untranslated region (UTR) of 526 bp, a 3?? UTR of 377 bp and an open reading frame (ORF) of 507 bp, encoding a protein of 168 amino acid residues, which contained two signature sequences of TCTP family. Its deduced amino acid sequence was similar to the other known plants TCTPs in a range of 77.4?C92.3%. Expression of JcTCTP was the highest in the stem, endosperm at embryo formation stage and embryo of J. curcas tissues, and the lowest in the endosperm at seminal leaf embryo stage and flower, demonstrating a pattern of temporal and spatial specific expression.     

In vitro polyploidization from shoot tips of Jatropha curcas L.: a biodiesel plant

Jatropha curcas L. has been considered one of the most promising alternatives for biofuel production and, thus, a relevant economic crop. In this context, in vitro tissue culture techniques such as organogenesis and embryogenesis have been conducted for mass clonal propagation of elite J. curcas lines. However, despite advancements, in vitro induction of polyploids has not yet been related for this crop. In this sense, the present study attempted to induce polyploidy in plantlets generated from shoot tips of J. curcas ??Gon?alo?? (2n?=?2×?=?22 chromosomes, 2C?=?0.85?pg). For this purpose, some criteria were adopted for selection of the most adequate colchicine treatment: (a) survival rate of the explants, and (b) number of tetraploid and (c) mixoploid plantlets. Tetraploid and mixoploid plantlets were obtained from different treatments, with 0.5?mM colchicine for 96?h being the most efficient. The plantlets were recovered and clonally propagated in tissue culture medium supplemented with indole-3-acetic acid and 6-benzylaminopurine. These results show that the tissue culture procedures were adequate for induction, propagation and recovery of tetraploid and mixoploid plantlets. Moreover, DNA ploidy level screening by flow cytometry was a practical and rapid strategy for selection of diploid, mixoploid and tetraploid plantlets. The tissue culture system presented here represents a reliable methodology for in vitro polyploid induction of this and other elite lines of J. curcas.     

A promoter analysis of MOTHER OF FT AND TFL1 1 (JcMFT1), a seed-preferential gene from the biofuel plant Jatropha curcas

MOTHER OF FT AND TFL1 (MFT)-like genes belong to the phosphatidylethanoamine-binding protein (PEBP) gene family in plants. In contrast to their homologs FLOWERING LOCUS T (FT)-like and TERMINAL FLOWER 1 (TFL1)-like genes, which are involved in the regulation of the flowering time pathway, MFT-like genes function mainly during seed development and germination. In this study, a full-length cDNA of the MFT-like gene JcMFT1 from the biodiesel plant Jatropha curcas (L.) was isolated and found to be highly expressed in seeds. The promoter of JcMFT1 was cloned and characterized in transgenic Arabidopsis. A histochemical β-glucuronidase (GUS) assay indicated that the JcMFT1 promoter was predominantly expressed in both embryos and endosperms of transgenic Arabidopsis seeds. Fluorometric GUS analysis revealed that the JcMFT1 promoter was highly active at the mid to late stages of seed development. After seed germination, the JcMFT1 promoter activity decreased gradually. In addition, both the JcMFT1 expression in germinating Jatropha embryos and its promoter activity in germinating Arabidopsis embryos were induced by abscisic acid (ABA), possibly due to two ABA-responsive elements, a G-box and an RY repeat, in the JcMFT1 promoter region. These results show that the JcMFT1 promoter is seed-preferential and can be used to control transgene expression in the seeds of Jatropha and other transgenic plants.     

High-frequency plant regeneration from leaf-disc cultures of Jatropha curcas L.: an important biodiesel plant

A simple, high-frequency and reproducible protocol for induction of adventitious shoot buds and plant regeneration from leaf-disc cultures of Jatropha curcas L. has been developed. Adventitious shoot buds were induced from very young leaf explants of in vitro germinated seedlings as well as mature field-grown plants cultured on Murashige and Skoog’s (MS) medium supplemented with thidiazuron (TDZ) (2.27 μM), 6-benzylaminopurine (BA) (2.22 μM) and indole-3-butyric acid (IBA) (0.49 μM). The presence of TDZ in the induction medium has greater influence on the induction of adventitious shoot buds, whereas BA in the absence of TDZ promoted callus induction rather than shoot buds. Induced shoot buds were multiplied and elongated into shoots following transfer to the MS medium supplemented with BA (4.44 μM), kinetin (Kn) (2.33 μM), indole-3-acetic acid (IAA) (1.43 μM), and gibberellic acid (GA₃) (0.72 μM). Well-developed shoots were rooted on MS medium supplemented with IBA (0.5 μM) after 30 days. Regenerated plants after 2 months of acclimatization were successfully transferred to the field without visible morphological variation. This protocol might find use in mass production of true-to-type plants and in production of transgenic plants through Agrobacterium/biolistic-mediated transformation.     

Morphogenesis and plant regeneration from tissue cultures of Jatropha curcas

Techniques for the regeneration of Jatropha curcas L. from various explants have been developed. Regeneration from hypocotyl, petiole and leaf explants was evaluated on a range of concentrations of zeatin, kinetin and N⁶ benzyladenine (BA) either singly or in combination with indole-3-butyric acid (IBA). Higher regeneration from hypocotyl and petiole explants was obtained on BA with IBA than on zeatin- or kinetin-supplemented media. Leaf discs from the third expanding leaf exhibited higher regeneration potential than those from the fourth leaf. Independent of the explant type, direct adventitious shoot bud induction was recorded highest on MS medium with 2.22 M BA and 4.9 M IBA. Although the same BA concentration but with reduced IBA concentration (0.49 M) proved effective in callus mediated regeneration from hypocotyl and leaf explants, the petioles required lower concentrations of the two growth regulators (0.44 M BA and 0.49 M IBA). Regenerated shoots could be rooted on growth regulator-free gelled full-strength MS medium. Following simple hardening procedures, the in vitro-raised plants could be transferred to soil and grown to maturity in the field.Abbreviations BA N⁶ benzyladenine - IAA indole-3-acetic acid - IBA indole-3-butyric acid - MS Murashige & Skoog's (1962) medium - NAA -naphthaleneacetic acid     

麻风树LEC1基因的生物信息学分析

LEC1是调控植物种子发育过程和油脂产量的重要基因。本文选择功能已知的拟南芥LEC1基因为参考序列,对麻风树LEC1基因开展了蛋白组分和理化性质分析,蛋白结构和功能预测,系统进化分析等生物信息学研究,为进一步研究麻风树LEC1基因的生物学功能奠定了基础。     

Growth,reproductive phenology and yield responses of a potential biofuel plant,Jatropha curcas grown under projected 2050 levels of elevated CO2

Jatropha (Jatropha curcas) is a non‐edible oil producing plant which is being advocated as an alternative biofuel energy resource. Its ability to grow in diverse soil conditions and minimal requirements of essential agronomical inputs compared with other oilseed crops makes it viable for cost‐effective advanced biofuel production. We designed a study to investigate the effects of elevated carbon dioxide concentration ([CO₂]) (550 ppm) on the growth, reproductive development, source‐sink relationships, fruit and seed yield of J. curcas. We report, for the first time that elevated CO₂ significantly influences reproductive characteristics of Jatropha and improve its fruit and seed yields. Net photosynthetic rate of Jatropha was 50% higher in plants grown in elevated CO₂ compared with field and ambient CO₂‐grown plants. The study also revealed that elevated CO₂ atmosphere significantly increased female to male flower ratio, above ground biomass and carbon sequestration potential in Jatropha (24 kg carbon per tree) after 1 year. Our data demonstrate that J. curcas was able to sustain enhanced rate of photosynthesis in elevated CO₂ conditions as it had sufficient sink strength to balance the increased biomass yields. Our study also elucidates that the economically important traits including fruit and seed yield in elevated CO₂ conditions were significantly high in J. curcas that holds great promise as a potential biofuel tree species for the future high CO₂ world.     

Physical wounding-assisted Agrobacterium-mediated transformation of juvenile cotyledons of a biodiesel-producing plant, Jatropha curcas L.

The non-edible plant Jatropha curcas L. is one of the most promising feedstock for sustainable biodiesel production as it is not a source of edible vegetable oils, produces high amounts of oil (approx. 30–60% in dry seeds) and does not require high-cost maintenance. However, as with other undomesticated crops, the cultivation of J. curcas presents several drawbacks, such as low productivity and susceptibility to pests. Hence, varietal improvement by genetic engineering is essential if J. curcas is to become a viable alternative source of biodiesel. There is to date no well-established and efficient transformation system for J. curcas. In this study, we tested various physical wounding treatments, such as sonication and sand-vortexing, with the aim of developing an efficient Agrobacterium-mediated transformation for J. curcas. The highest stable transformation rate (53%) was achieved when explants were subjected to 1 min of sonication followed by 9 min of shaking in Agrobacterium suspension. The transformation frequency achieved using this protocol is the highest yet reported for J. curcas.     

Kibdelosporangium phytohabitans sp. nov., a novel endophytic actinomycete isolated from oil-seed plant Jatropha curcas L. containing 1-aminocyclopropane-1-carboxylic acid deaminase

A novel actinomycete, designated strain KLBMP 1111^T, was isolated from the root of the oil-seed plant Jatropha curcas L. collected from Sichuan Province, south-west China. Strain KLBMP 1111^T formed a distinct branch in the 16S rRNA gene phylogenetic tree together with the type strains in the genus Kibdelosporangium, with the highest similarity to Kibdelosporangium aridum subsp. aridum DSM 43828^T (98.8%), K. aridum subsp. largum DSM 44150^T (98.1%) and Kibdelosporangium philippinense DSM 44226^T (98.1%). The organism produced sporangium-like structures, the typical morphological characteristic of the genus Kibdelosporangium. The chemotaxonomic properties of this strain were also consistent with those of the genus Kibdelosporangium: the peptidoglycan contained meso-diaminopimelic acid; the predominant menaquinone was MK-9(H₄); phospholipids were phosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine, phosphatidylinositol and an unknown phospholipid; iso-C_16:0, C_16:0, anteiso-C_15:0 and iso-C_15:0 as the predominant cellular fatty acids and the G+C content was 67.2 mol%. DNA–DNA hybridization values between strain KLBMP 1111^T and the three Kibdelosporangium species were less than 50%. This strain had the ability to produce a siderophore, utilized 1-aminocyclopropane-1-carboxylic acid (ACC) as sole source of nitrogen and possessed ACC deaminase enzyme. Based on genotypic and phenotypic data, strain KLBMP 1111^T represents a novel species in the genus Kibdelosporangium. We propose the name Kibdelosporangium phytohabitans sp. nov. for this species. The type strain is the strain KLBMP 1111^T (=KCTC 19775^T = CCTCC AA 2010001^T).     

Integrated genome sequence and linkage map of physic nut (Jatropha curcas L.), a biodiesel plant

The family Euphorbiaceae includes some of the most efficient biomass accumulators. Whole genome sequencing and the development of genetic maps of these species are important components in molecular breeding and genetic improvement. Here we report the draft genome of physic nut (Jatropha curcas L.), a biodiesel plant. The assembled genome has a total length of 320.5 Mbp and contains 27 172 putative protein‐coding genes. We established a linkage map containing 1208 markers and anchored the genome assembly (81.7%) to this map to produce 11 pseudochromosomes. After gene family clustering, 15 268 families were identified, of which 13 887 existed in the castor bean genome. Analysis of the genome highlighted specific expansion and contraction of a number of gene families during the evolution of this species, including the ribosome‐inactivating proteins and oil biosynthesis pathway enzymes. The genomic sequence and linkage map provide a valuable resource not only for fundamental and applied research on physic nut but also for evolutionary and comparative genomics analysis, particularly in the Euphorbiaceae.