Improvement of regeneration in pepper: a recalcitrant species

[EN] Organogenesis is influenced by factors like genotype, type of explant, culture medium components, and incubation conditions. The influence of ethylene, which can be produced in the culture process, can also be a limiting factor in recalcitrant species like pepper. In this work, bud induction was achieved from cotyledons and hypocotyls-from eight pepper cultivars-on Murashige and Skoog (MS) medium supplemented with 22.2 mu M 6-benzyladenine (6BA) and 5.71 mu M indole-3-acetic acid (IAA), in media with or without silver nitrate (SN) (58.86 mu M), a suppressor of ethylene action. In the SN-supplemented medium, the frequencies of explants with buds and with callus formation were lower in both kinds of explant, but higher numbers of developed shoots were isolated from explants cultured on SN. Bud elongation was better in medium with gibberellic acid (GA(3)) (2.88 mu M) than in medium free of growth regulators or supplemented with 1-aminocyclopropane-1-carboxylic acid (ACC) at 34.5 mu M. However, isolation of shoots was difficult and few plants were recovered. The effect of adding SN following bud induction (at 7 d) and that of dark incubation (the first 7 d of culture) was also assessed in order to improve the previous results. When SN was added after bud induction, similar percentages of bud induction were found for cotyledons (average frequency 89.37% without SN and 94.37% with SN) whereas they doubled in hypocotyls (50% without SN and 87.7% with SN). In addition, in both kinds of explant, the number of developed plants able to be transferred to soil (developed and rooted) was greatly increased by SN. Dark incubation does not seem to improve organogenesis in pepper, and hypocotyl explants clearly represent a better explant choice-with respect to cotyledonary explants-for the pepper cultivars assayed.We thank the COMAV germplasm bank at Universitat Politecnica de Valencia and the Arid Lands Institute for pepper seeds and the Tunisian Ministry of Higher Education and Scientific Research who fund N. Gammoudi's stay.Gammoudi, N.; San Pedro-Galan, T.; Ferchichi, A.; Gisbert Domenech, MC. (2018). Improvement of regeneration in pepper: a recalcitrant species. In Vitro Cellular & Developmental Biology - Plant. 54(2):145-153. https://doi.org/10.1007/s11627-017-9838-1S145153542Ashrafuzzaman M, Hossain MM, Razi Ismail M, Shahidul Haque M, Shahidullah SM, Uz Zaman S (2009) Regeneration potential of seedling explants of chilli (Capsicum annuum). Afr J Biotechnol 8:591–596Bortesi L, Fischer R (2015) The CRISPR/Cas9 system for plant genome editing and beyond. Biotechnol Adv 33:41–52Brooks C, Nekrasov V, Lippman ZB, Van Eck J (2014) Efficient gene editing in tomato in the first generation using the clustered regularly interspaced short palindromic repeats/CRISPR-associated9 system. Plant Physiol 166:1292–1297Brown DC, Thorpe TA (1995) Crop improvement through tissue culture. World J Microbiol Biotechnol 11:409–415Carvalho MAF, Paiva R, Stein VC, Herrera RC, Porto JMP, Vargas DP, Alves E (2014) Induction and morpho-ultrastructural analysis of organogenic calli of a wild passion fruit. Braz Arch Biol Technol 57:581–859Christopher T, Rajam MV (1996) Effect of genotype, explant and medium on in vitro regeneration of red pepper. Plant CellTiss Org Cult 46:245–250Dabauza M, Peña L (2001) High efficiency organogenesis in sweet pepper (Capsicum annuum L.) tissues from different seedling explants. Plant Growth Regul 33:221–229De Filippis LF (2014) Crop improvement through tissue culture. In: Ahmad P, Wani MR, Azooz MM, Tran LSP (eds) Improvement of crops in the era of climate changes, vol 1. Springer, New York, pp 289–346Gammoudi N, Ben Yahia L, Lachiheb B, Ferchichi A (2016) Salt response in pepper (Capsicum annuum L.): components of photosynthesis inhibition, proline accumulation and K+/Na+ selectivity. JJ Aridland Agri 2:1–12González A, Arigita L, Majada J, Sánchez Tamés R (1997) Ethylene involvement in in vitro organogenesis and plant growth of Populus tremula L. Plant Growth Regul 22:1–6Grozeva S, Rodeva V, Todorova V (2012) In vitro shoot organogenesis in Bulgarian sweet pepper (Capsicum annuum L.) varieties. EJBio 8:39–44Gunay AL, Rao PS (1978) In vitro plant regeneration from hypocotyls and cotyledon explants of red pepper (Capsicum). Plant Sci Lett 11:365–372Huxter TJ, Thorpe TA, Reid DM (1981) Shoot initiation in light- and dark-grown tobacco callus: the role of ethylene. Physiol Plant 53:319–326Hyde CL, Phillips GC (1996) Silver nitrate promotes shoot development and plant regeneration of chile pepper (Capsicum annuum L.) via organogenesis. In Vitro-Plant 32:72–80Kothari SL, Joshi A, Kachhwaha S, Ochoa-Alejo N (2010) Chilli peppers—a review on tissue culture and transgenesis. Biotechnol Adv 28:35–48Kumar AO, Rupavathi T, Tata SS (2012) Adventitious shoot bud induction in chili pepper (Capsicum annuum L. cv. X-235). In J Sci Nat 3:192–196Kumar PP, Lakshmanan P, Thorpe TA (1998) Regulation of morphogenesis in plant tissue culture by ethylene. In Vitro Cell Dev Biol Plant 34:94–103Liu W, Parrott WA, Hildebrand DF, Collins GB, Williams EG (1990) Agrobacterium induced gall formation in bell pepper (Capsicum annuum L.) and formation of shoot-like structures expressing introduced genes. Plant Cell Rep 9:360–364Maligeppagol M, Manjula R, Navale PM, Babu KP, Kumbar BM, Laxman RH (2016) Genetic transformation of chilli (Capsicum annuum L.) with Dreb1A transcription factor known to impart drought tolerance. Indian J Biotechnol 15:17–24Mantiri FR, Kurdyukov S, Chen SK, Rose RJ (2008) The transcription factor MtSERF1 may function as a nexus between stress and development in somatic embryogenesis in Medicago truncatula. Plant Signal Behav 3:498–500Mezghani N, Jemmali A, Elloumi N, Gargouri-Bouzid R, Kintzios S (2007) Morpho-histological study on shoot bud regeneration in cotyledon cultures of pepper (Capsicum annuum). Biologia 62:704–710Mohamed-Yasseen Y (2001) Influence of agar and activated charcoal on uptake of gibberellin and plant morphogenesis in vitro. In Vitro Cell Dev Biol - Plant 37:204–205Moshkov IE, Novikova GV, Hall MA, George EF (2008) Plant growth regulators III: ethylene. In: George EF, Hall MA, Klerk G-JD (eds) Plant propagation by tissue culture, vol 1, 3rdedn. Springer, Dordrecht, The Netherlands, pp 239–248Murashige T, Skoog F (1962) A revised medium for rapid growth and bioassays with tobacco tissue cultures. Physiol Plant 15:473–497Nogueira RC, Paiva R, de Oliveira LM, Soares GA, Soares FP, Castro AHF, Paiva PDO (2007) Calli induction from leaf explants of murici-pequeno (Byrsonima intermedia A. Juss.) Ciênc Agrotec 31:366–370Ochoa-Alejo N, Ramirez-Malagon R (2001) In vitro chili pepper biotechnology. In Vitro Cell Devl Biol Plant 37:701–729Orlińska M, Nowaczy P (2015) In vitro plant regeneration of 4 Capsicum spp. genotypes using different explant types. Turk J Biol 39:60–68Reid MS (1995) Ethylene in plant growth, development and senescence. In: Davies PJ (ed) Plant hormones: physiology, biochemistry and molecular biology, 2nd edn. Kluwer Acad Publ, Dordrecht, The Netherlands, pp 486–508Sanatombi K, Sharma GJ (2008) In vitro plant regeneration in six cultivars of Capsicum spp. using different explants. Biol Plant 52:141–145Santana-Buzzy N, Canto-Flick A, Barahona-Pérez F, Montalvo-Peniche MC, Zapata-Castillo PY, Solís-Ruiz A, Zaldívar-Collí A, Gutiérrez-Alonso O, Miranda-Ham ML (2005) Regeneration of habanero pepper (Capsicum chinense Jacq.) via organogenesis. Hortscience 40:1829–1831Santana-Buzzy N, Canto-Flick A, Iglesias-Andreu LG, Montalvo-Peniche MC, López-Puc G, Barahona-Pérez F (2006) Improvement of in vitro culturing of habanero pepper by inhibition of ethylene effects. Hortscience 41:405–409Sawai S, Ohyama K, Yasumoto S, Seki H, Sakuma T, Yamamoto T, Takebayashi Y, Kojima M, Sakakibara H, Aoki T, Muranaka T, Saito K, Umemoto N (2014) Sterol side chain reductase 2 is a key enzyme in the biosynthesis of cholesterol, the common precursor of toxic steroidal glycoalkaloids in potato. Plant Cell 26:3763–3774Shah SH, Ali S, Jan SA, Din J, Ali GM (2014) Assessment of silver nitrate on callus induction and in vitro shoot regeneration in tomato (Solanum lycopersicum Mill.) Pakistan J Bot 46:2163–2172Steinitz B, Wolf D, Matzevitch-Josef T, Zelcer A (1999) Regeneration in vitro and genetic transformation of pepper (Capsicum spp.): the current state of the art. Capsicum Eggplant Plant Newsletter 18:9–15Tamimi SM (2015) Effects of ethylene inhibitors, silver nitrate (AgNO3), cobalt chloride (CoCl2) and aminooxyacetic acid (AOA), on in vitro shoot induction and rooting of banana (Musa acuminata L.) Afr J Biotechnol 14:2510–2516Trujillo-Moya C, Gisbert C (2012) The influence of ethylene and ethylene modulators on shoot organogenesis in tomato. Plant Cell Tissue Organ Cult 111:41–48Yasmin S, Mensuali-Sodi A, Perata P, Pucciariello C (2014) Ethylene influences in vitro regeneration frequency in the FR13A rice harbouring the SUB1A gene. Plant Growth Reg 72:97–103Zhao Y, Stiles AR, Saxena PK, Liu CZ (2013) Dark preincubation improves shoot organogenesis from Rhodiola crenulata leaf explants. Biol Plant 57:189–19

X-ray emission from the Sombrero galaxy: discrete sources

We present a study of discrete X-ray sources in and around the bulge-dominated, massive Sa galaxy, Sombrero (M104), based on new and archival Chandra observations with a total exposure of ~200 ks. With a detection limit of L_X = 1E37 erg/s and a field of view covering a galactocentric radius of ~30 kpc (11.5 arcminute), 383 sources are detected. Cross-correlation with Spitler et al.'s catalogue of Sombrero globular clusters (GCs) identified from HST/ACS observations reveals 41 X-rays sources in GCs, presumably low-mass X-ray binaries (LMXBs). We quantify the differential luminosity functions (LFs) for both the detected GC and field LMXBs, whose power-low indices (~1.1 for the GC-LF and ~1.6 for field-LF) are consistent with previous studies for elliptical galaxies. With precise sky positions of the GCs without a detected X-ray source, we further quantify, through a fluctuation analysis, the GC LF at fainter luminosities down to 1E35 erg/s. The derived index rules out a faint-end slope flatter than 1.1 at a 2 sigma significance, contrary to recent findings in several elliptical galaxies and the bulge of M31. On the other hand, the 2-6 keV unresolved emission places a tight constraint on the field LF, implying a flattened index of ~1.0 below 1E37 erg/s. We also detect 101 sources in the halo of Sombrero. The presence of these sources cannot be interpreted as galactic LMXBs whose spatial distribution empirically follows the starlight. Their number is also higher than the expected number of cosmic AGNs (52+/-11 [1 sigma]) whose surface density is constrained by deep X-ray surveys. We suggest that either the cosmic X-ray background is unusually high in the direction of Sombrero, or a distinct population of X-ray sources is present in the halo of Sombrero.Comment: 11 figures, 5 tables, ApJ in pres

Performance of the CMS Cathode Strip Chambers with Cosmic Rays

The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

Genotoxic potential generated by biomass burning in the Brazilian Legal Amazon by Tradescantia micronucleus bioassay: a toxicity assessment study

<p>Abstract</p> <p>Background</p> <p>The Brazilian Amazon has suffered impacts from non-sustainable economic development, especially owing to the expansion of agricultural commodities into forest areas. The Tangará da Serra region, located in the southern of the Legal Amazon, is characterized by non-mechanized sugar cane production. In addition, it lies on the dispersion path of the pollution plume generated by biomass burning. The aim of this study was to assess the genotoxic potential of the atmosphere in the Tangará da Serra region, using <it>Tradescantia pallida </it>as <it>in situ </it>bioindicator.</p> <p>Methods</p> <p>The study was conducted during the dry and rainy seasons, where the plants were exposed to two types of exposure, active and passive.</p> <p>Results</p> <p>The results showed that in all the sampling seasons, irrespective of exposure type, there was an increase in micronucleus frequency, compared to control and that it was statistically significant in the dry season. A strong and significant relationship was also observed between the increase in micronucleus incidence and the rise in fine particulate matter, and hospital morbidity from respiratory diseases in children.</p> <p>Conclusions</p> <p>Based on the results, we demonstrated that pollutants generated by biomass burning in the Brazilian Amazon can induce genetic damage in test plants that was more prominent during dry season, and correlated with the level of particulates and elevated respiratory morbidity.</p

Sleep study, respiratory mechanics, chemosensitive response and quality of life in morbidly obese patients undergoing bariatric surgery: a prospective, randomized, controlled trial

<p>Abstract</p> <p>Background</p> <p>Obesity is a major public health problem in both developed and developing countries alike and leads to a series of changes in respiratory physiology. There is a strong correlation between obesity and cardiopulmonary sleep disorders. Weight loss among such patients leads to a reduction in these alterations in respiratory physiology, but clinical treatment is not effective for a long period of time. Thus, bariatric surgery is a viable option.</p> <p>Methods/Design</p> <p>The present study involves patients with morbid obesity (BMI of 40 kg/m²or 35 kg/m²to 39.9 kg/m²with comorbidities), candidates for bariatric surgery, screened at the Santa Casa de Misericórdia Hospital in the city of Sao Paulo (Brazil). The inclusion criteria are grade III morbid obesity, an indication for bariatric surgery, agreement to participate in the study and a signed term of informed consent. The exclusion criteria are BMI above 55 kg/m², clinically significant or unstable mental health concerns, an unrealistic postoperative target weight and/or unrealistic expectations of surgical treatment. Bariatric surgery candidates who meet the inclusion criteria will be referred to Santa Casa de Misericórdia Hospital and will be reviewed again 30, 90 and 360 days following surgery. Data collection will involve patient records, personal data collection, objective assessment of HR, BP, neck circumference, chest and abdomen, collection and analysis of clinical preoperative findings, polysomnography, pulmonary function test and a questionnaire on sleepiness.</p> <p>Discussion</p> <p>This paper describes a randomised controlled trial of morbidly obese patients. Polysomnography, respiratory mechanics, chemosensitive response and quality of life will be assessed in patients undergoing or not undergoing bariatric surgery.</p> <p>Trial Registration</p> <p>The protocol for this study is registered with the Brazilian Registry of Clinical Trials - ReBEC (RBR-9k9hhv).</p