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Somatic embryogenesis receptor-like kinase 1 (SERK1) is a membrane receptor that might serve as common co-regulator of plant cell differentiation processes by forming heterodimers with specific receptor-like kinases. The Coffea canephora SERK1 homolog (CcSERK1) was cloned in this work, and its early function in the transcription of embryogenesis master genes and of genes encoding proteins involved in auxin metabolism was investigated by externally manipulating its expression in embryogenic leaf explants, before the appearance of embryogenic structures. Overexpression of CcSERK1 early during embryogenesis caused an increase in the number of somatic embryos when the 55-day process was completed. Suppression of CcSERK1 expression by RNA interference almost abolished somatic embryogenesis. Real time-PCR experiments revealed that the transcription of the CcAGL15, CcWUS, CcBBM, CcPKL, CcYUC1, CcPIN1 and CcPIN4 homologs was modified in direct proportion to the expression of CcSERK1 and that only CcLEC1 was inversely affected by the expression levels of CcSERK1. The expression of the CcYUC4 homolog was induced to more than 80-fold under CcSERK1 overexpression conditions, but it was also induced when CcSERK1 expression was silenced. The level of CcTIR1 was not affected by CcSERK1 overexpression but was almost abolished during CcSERK1 silencing. These results suggest that CcSERK1 co-regulates the induction of somatic embryogenesis in Coffea canephora by early activation of YUC-dependent auxin biosynthesis, auxin transport mediated by PIN1 and PIN4, and probably auxin perception by the TIR1 receptor, leading to the induction of early-stage homeotic genes (CcAGL15, CcWUS, CcPKL and CcBBM) and repression of late-stage homeotic genes (CcLec1)., (© 2018 Scandinavian Plant Physiology Society.)

Pentalinon andrieuxii is a species used in Mayan traditional medicine due to its biological properties. Recent studies indicate that it produces a pentacyclic triterpene-denominated betulinic acid, which presents various biological activities: antibacterial, antifungal, antiplasmodial, anti-inflammatory, antimalarial, anticancer, leishmanicidal, and antiviral, as well as steroids and sterols with leishmanicidal properties. A recent study also reported the presence of urechitol A and B in the roots; these are secondary metabolites whose biochemical function is as yet unknown. This plant therefore represents a natural source of metabolites with potential application in the pharmaceutical industry. In this chapter, a protocol is described for obtaining transgenic plants, at the reporter gene of the β-glucuronidase (GUS) via Agrobacterium tumefaciens from hypocotyl and root explants. The protocol established herein could be employed for the manipulation of the genes involved in the biosynthesis of isoprenoids or secondary metabolites of interest. To our knowledge, this is the first report of stable transformation of Pentalinon andrieuxii via Agrobacterium tumefaciens.

Commercialization of agricultural products, including seeds and its derived products, represents an important economic source for developing countries. Natural colorants obtained from the seeds of achiote plant (annatto) have been used since pre-Hispanic times. Also, production of this crop has been important for Mayan cuisine. Annual world production of achiote seeds is approximately 14,500 tons (dry weight). Two thirds of the production is commercialized as dried seeds and the rest as colorant. Latin America produces 60% of the total world production, followed by Africa (27%) and Asia (12%). The main producers in Latin America are Peru, Brazil and Mexico. The purpose of the present paper is to review the most recent literature on Bixa orellana L. focusing on bixin, norbixin, tocotrienols and tocopherols biosynthesis, use and industrial applications of annatto extracts, as well as its nutraceutical potential and its benefits for human health.

The biosynthesis of lupeol-3-(3'R-hydroxy)-stearate (procrim b, 1) was investigated in the Mexican medicinal plant Pentalinon andrieuxii by (13)CO2 pulse-chase experiments. NMR analyses revealed positional enrichments of (13)C2-isotopologues in both the triterpenoid and the hydroxystearate moieties of 1. Five of the six isoprene units reflected a pattern with [1,2-(13)C2]- and [3,5-(13)C2]-isotopologues from the respective C5-precursors, IPP and DMAPP, whereas one isoprene unit in the ring E of 1 showed only the [3,5-(13)C2]-connectivity of the original C5-precursor, due to rearrangement of the dammarenyl cation intermediate during the cyclization process. The presence of (13)C2-isotopologues was indicative of [(13)C2]acetyl-CoA being the precursor units in the formation of the fatty acid moiety and of the triterpene via the mevalonate route. The observed labeling pattern was in agreement with a chair-chair-chair-boat conformation of the (S)-2,3-oxidosqualene precursor during the cyclization process, suggesting that the lupeol synthase from P. andrieuxii is of the same type as that from Olea europea and Taraxacum officinale, but different from that of Arabidopsis thaliana. The study shows that (13)CO2 pulse-chase experiments are powerful in elucidating, under in vivo conditions and in a single experiment, the biosynthesis of complex plant products including higher terpenes.

The main parameters for the estimation of growth within in vitro cultures are reviewed. Procedures to measure these parameters are described, emphasizing in each case their convenience of use, depending on the features of the culture evaluated.

The main parameters for the estimation of growth within in vitro cultures are reviewed. Procedures to measure these parameters are described, emphasizing in each case their convenience of use, depending on the features of the culture to evaluate.

Addition of various concentrations (0.5-20 mM) of acetylsalicylic acid (ASA) to tumor lines ofCatharanthus roseus cultivatedin vitro and requiring corn starch as carbon source, produced remarkable effects on secondary metabolite production. An increase of 505% total alkaloids per culture (cells plus liquid medium), 1587% total phenolics (liquid medium), 612% total furanocoumarins (liquid medium) and 1476% total anthocyanins (liquid medium) was detected. 1 mM ASA in combination with other elicitors, such as homogenates ofAspergillus fumigatus or trans-cinnamic acid, did not further increase the metabolite content substantially. The results suggest that ASA could act as a new biotic elicitor of metabolite production inC. roseus cell suspension culture.

The addition of Aspergillus niger homogenate to Catharanthus roseus cell suspension cultures produced an increment of more than 60% in the alkaloid content of two different cell lines. The use of an inhibitor of phenylalanine ammonia lyase, i. e. cinnamic acid, along with the homogenate, resulted in an appearance of 90% of the alkaloids in the medium. Furthermore, even in the absence of fungal homogenate, there was a marked increase in the alkaloid content. The exposure of the cells to an osmotic stress produced a marked increment (320%) in the total alkaloid content. When both stress treatments were applied sequentially, an additive effect on alkaloid accumulation was observed. It was 300% higher than in cells cultured without treatment, the majority of the alkaloids found in the medium.