Differential expression of cysteine peptidase genes in the inner integument and endosperm of developing seeds of Jatropha curcas L. (Euphorbiaceae).

In several plant tissues, programmed cell death (PCD) is mediated by the combined action of cysteine peptidases, namely KDEL-tailed cysteine peptidases (KDEL-CysEP) and vacuolar processing enzymes (VPE). Here, we performed a search of the draft genome of Jatropha curcas L. (Euphorbiaceae) and identified 2 genes for KDEL-CysEP (Jc-CysEP1 and Jc-CysEP2) and 3 genes for VPE (Jc-ßVPE, Jc-γVPE and Jc-δVPE) and determined the expression patterns of these genes by RT-qPCR in integument and cellular endosperm of seeds collected at seven different developmental stages. We were able to demonstrate that the expression of Jc-CysEP1, Jc-CysEP2, Jc-ßVPE and Jc-γVPE proceeded rapidly from Stage IV, with Jc-CysEP2 displaying the highest relative expression; expression of Jc-δVPE could not be detected in any of the tissues/developmental stages analyzed. Additionally, we showed that the expression pattern of these peptidases correlates with anatomical changes in integument and cellular endosperm, thus suggesting a role for both classes of peptidases in PCD and in protein processing, both of which occur simultaneously in each of these tissues.

Bioaccumulation of nutrient elements from fly ash-amended soil in Jatropha curcas L.: a biofuel crop.

Fly ash (FA) from coal-burning industries may be a potential inorganic soil amendment; the insight of its nutrient release and supply to soil may enhance their agricultural use. The study was conducted to assess the ability of fly ash (a coal fired thermal plant waste) to reduce soil fertility depletion and to study bioaccumulation of mineral nutrients in Jatropha curcas grown on soils amended with fly ash. Fly ash was amended to field soil at six rates (0, 5, 10, 20, 40, and 70 % w/w) on which J. curcas was grown. After 8 months of growth, the height of jatropha plants was significantly increased at 5 and 10 % FA-amended soil, whereas, biomass significantly increased at 5, 10, and 20 % FA-amended soil compared to control soil (0 % FA). Leaf nutrients uptake, followed by stems and roots uptake were highly affected by fly ash amendment to soil. Most of nutrients accumulation were increased up to 20 % fly ash and decreased thereafter. The results of available nutrient analysis of soil revealed that availability of nitrogen, potassium, sulfur, copper, iron, mangnese, and zinc declined significantly at higher levels of fly ash amendments, whereas, availability of phosphorus increased at these levels. However, pH, organic carbon, and available boron were not influenced significantly by fly ash amendment to soil. Microbial biomass C, N, and ratio of microbial-C to organic C were significantly reduced at 20 % fly ash and higher amounts. This study revealed that J. curcas plants could gainfully utilize the nutrients available in fly ash by subsequently amending soil.

Antifeedant effect of Jatropha gossypifolia senescent leaf extract on Spodoptera exigua.

Spodoptera exigua is one of the economic polyphagous pests that is widespread and has been able to develop rapid resistance, thus the development of pest control strategies are required urgently. Botanical insecticides have long been touted as attractive alternatives to synthetic chemical insecticides for pest management because the former pose little threat to the environment or to human health. This research studied the antifeeding effect of Jatropha gossypifolia senescent leaf extract on second instar larvae. J. gossypifolia leaves were extracted using a Soxhlet apparatus with ethanol as the solvent. Concentration in the range from 1 to 4 mg/mL was mixed with the artificial diet and then was put on a plate with the control diet as choice and no-choice assays. A dual standard check was run along with the treatment using no solvent (control A) and ethanol (control B). The mortality and behavior of larvae were observed every day whereas the weight of larvae was observed every 3 days. Observation continued until the larvae developed into the pupal stage. In the no-choice assay, at 4 mg/mL concentration, absolute mortality (100%) was recorded 17 days post-treatment. All concentrations showed toxicity at the first day of exposure. No toxicity was recorded in the control A or B groups. In the choice assay, the results showed that 70-85% of larvae seemed to ignore consumption of the treated diets. Larvae mortality occurred after 3 days of exposure, especially for the larvae that fed on the treated diet. The weight and rate of weight increase of the larvae feeding preferentially on the treated diet were less than for the control diet. However, when larvae moved to feed on the control diet, there was an increase in the rate of weight increase. Larvae that preferred to feed on the control diet reached the adult stage faster than larvae that preferred feeding on the treated diet. In addition, the treated diet produced some abnormal larvae at metamorphosis in the pupal stage from both assays.

Regeneration of Jatropha curcas through efficient somatic embryogenesis and suspension culture.

.Using immature zygotic embryos as explants, we have developed an efficient method for somatic embryogenesis in three germplasm accessions collected from China, India and Indonesia. Indirect somatic embryogenesis was achieved when endosperm tissue and immature embryos between 0.5-1.0 cm in length were cultured in a medium with 2,4-D, preferably at 5-10 mg/l, followed by a shift to a hormone-free medium supplemented with glutamine and asparagine. Production of secondary embryos was improved by supplementing KNO3, glutamine and asparagine. 2,4-D (0.1-0.2 mg/l). PEG 8000 (5-10%) were essential for maintenance of embryogenic calli in liquid medium. Regeneration of soil-ready plants took as short as 3 months using the suspension cultures. Over 95% of the regenerated trees were able to flower and set seeds with no discernable morphological abnormality. This regeneration method is expected to facilitate the development of more efficient transformation system for Jatropha curcas.

Molecular approaches to improvement of Jatropha curcas Linn. as a sustainable energy crop.

With the increase in crude oil prices, climate change concerns and limited reserves of fossil fuel, attention has been diverted to alternate renewable energy sources such as biofuel and biomass. Among the potential biofuel crops, Jatropha curcas L, a non-domesticated shrub, has been gaining importance as the most promising oilseed, as it does not compete with the edible oil supplies. Economic relevance of J. curcas for biodiesel production has promoted world-wide prospecting of its germplasm for crop improvement and breeding. However, lack of adequate genetic variation and non-availability of improved varieties limited its prospects of being a successful energy crop. In this review, we present the progress made in molecular breeding approaches with particular reference to tissue culture and genetic transformation, genetic diversity assessment using molecular markers, large-scale transcriptome and proteome studies, identification of candidate genes for trait improvement, whole genome sequencing and the current interest by various public and private sector companies in commercial-scale cultivation, which highlights the revival of Jatropha as a sustainable energy crop. The information generated from molecular markers, transcriptome profiling and whole genome sequencing could accelerate the genetic upgradation of J. curcas through molecular breeding.

Nutritional, biochemical, and pharmaceutical potential of proteins and peptides from jatropha: review.

Increased bioenergy consciousness and high demand for animal products have propelled the search for alternative resources that could meet the dual demands. Jatropha seeds have potential to fit these roles in view of their multipurpose uses, broad climatic adaptability features, and high oil and protein contents. During the past five years many large-scale cultivation projects have been undertaken to produce jatropha seed oil as a feedstock for the biodiesel industry. The present review aims at providing biological significance of jatropha proteins and peptides along with their nutritional and therapeutic applications. The nutritional qualities of the kernel meal and protein concentrates or isolates prepared from seed cake are presented, enabling their efficient use in animal nutrition. In addition, (a) biologically active proteins involved in plant protection, for example, aquaporin and betaine aldehyde dehydrogenase, which have roles in drought resistance, and beta-glucanase, which has antifungal activity, as well as those having pharmaceutical properties, and (b) cyclic peptides with various biological activities such as antiproliferative, immunomodulatory, antifungal, and antimalarial activity are discussed. It is expected that the information collated will open avenues for new applications of proteins present in jatropha plant, thereby contributing to enhance the financial viability and sustainability of a jatropha-based biodiesel industry.