A rapid and efficient in vitro regeneration system for lettuce (Lactuca sativa L.)

Abstract Background Successful biotechnological improvement of crop plants requires a reliable and efficient in vitro regeneration system. Lettuce (Lactuca sativa L.), one the most important vegetable crops worldwide, is strongly genotype-dependent in terms of regeneration capacity, limiting the potential for biotechnological improvement of cultivars which show recalcitrance under currently available protocols. The effect of different nutrient sources, plant hormone combinations and activated charcoal supplementation on shoot induction efficiency was evaluated on the cultivar ‘RSL NFR’, which had previously shown poor regeneration efficiency. Results Multiple shoot organogenesis from cotyledon explants was recorded at the highest frequency and speed on Murashige and Skoog regeneration medium supplemented with 200 mg/l of activated charcoal, 3% sucrose, 10 mg/l benzylaminopurine and 0.5 mg/l naphthaleneacetic acid, which induced shoots through direct regeneration in 90.8 ± 7.9% of explants. High shoot induction efficiency was also observed, albeit not quantified, when using this medium on some other cultivars. Conclusions This activated charcoal-containing regeneration medium might offer a rapid and efficient option for direct shoot induction in some lettuce genotypes that do not respond well to common lettuce regeneration protocols. This is also the first report of the effect of activated charcoal in lettuce tissue culture

MOESM1 of A rapid and efficient in vitro regeneration system for lettuce (Lactuca sativa L.)

Additional file 1. A spreadsheet containing all raw data generated and analyzed during this study. The first sheet contains the data for cultivar ‘RSL NFR’ and the second sheet contains the data for cultivar ‘Winter Density’

Development and phytochemical characterization of high polyphenol red lettuce with anti-diabetic properties.

Polyphenol-rich Rutgers Scarlet Lettuce (RSL) (Lactuca sativa L.) was developed through somaclonal variation and selection in tissue culture. RSL may contain among the highest reported contents of polyphenols and antioxidants in the category of common fruits and vegetables (95.6 mg/g dry weight and 8.7 mg/g fresh weight gallic acid equivalents and 2721 µmol/g dry weight and 223 µmol/g fresh weight Trolox equivalents). Three main compounds accumulate at particularly high levels in RSL: chlorogenic acid, up to 27.6 mg/g dry weight, cyanidin malonyl-glucoside, up to 20.5 mg/g dry weight, and quercetin malonyl-glucoside, up to 35.7 mg/g dry weight. Major polyphenolic constituents of RSL have been associated with health promotion as well as anti-diabetic and/or anti-inflammatory activities. Daily oral administration of RSL (100 or 300 mg/kg) for up to eight days acutely reduced hyperglycemia and improved insulin sensitivity in high fat diet-induced obese hyperglycemic mice compared to vehicle (water) control. Data presented here support possible use of RSL as a functional food for the dietary management of diabetes

Phytochemical composition of Rutgers Scarlet Lettuce.

<p>Phytochemical composition of Rutgers Scarlet Lettuce.</p

Oral glucose tolerance test after Rutgers Scarlet Lettuce (RSL, line NFR-S-4) treatments.

<p>DIO mice were given daily oral administrations of RSL, water (vehicle), or Metformin for 7 days (<i>n</i> = 10, except Metformin group, <i>n</i> = 6). Mice were fasted for 6 h prior to an oral glucose challenge and blood glucose was recorded at indicated intervals. <b>A</b> Mean blood glucose (mg/dL) across time. <b>B</b> Mean change in blood glucose across time. <b>C</b> Area under the curve of the change in blood glucose across time. Data are presented as the mean ± SE. Significant differences vs vehicle control (* <i>p</i><0.05, ** <i>p</i><0.01, *** <i>p</i><0.001).</p

Smallpox subunit vaccine produced in Planta confers protection in mice

We report here the in planta production of the recombinant vaccinia virus B5 antigenic domain (pB5), an attractive component of a subunit vaccine against smallpox. The antigenic domain was expressed by using efficient transient and constitutive plant expression systems and tested by various immunization routes in two animal models. Whereas oral administration in mice or the minipig with collard-derived insoluble pB5 did not generate an anti-B5 immune response, intranasal administration of soluble pB5 led to a rise of B5-specific immunoglobulins, and parenteral immunization led to a strong anti-B5 immune response in both mice and the minipig. Mice immunized i.m. with pB5 generated an antibody response that reduced virus spread in vitro and conferred protection from challenge with a lethal dose of vaccinia virus. These results indicate the feasibility of producing safe and inexpensive subunit vaccines by using plant production systems

Development of Rutgers Scarlet Lettuce through plant tissue culture.

<p><b>A</b> Seed germination. <b>B</b> Cotyledon segments for callus induction. <b>C</b> Callus production. <b>D</b> Shoot regeneration from callus. <b>E</b> Shoot induction and selection for anthocyanin-rich phenotype. <b>F</b> Root induction from shoots.</p

Phytochemical content of Rutgers Scarlet Lettuce cultivars.

<p>DW: Dry weight basis; FW: Fresh weight basis.</p><p>Total polyphenols are reported as gallic acid equivalents ± SE.</p><p>Anthocyanins are reported as cyanidin 3-glucoside equivalents ± SE.</p><p>ORAC (oxygen radical absorbance capacity) values are reported as Trolox equivalents ± SE.</p><p>*Determined by Brunswick Labs (Southborough, MA).</p

Insulin sensitizing effects of Rutgers Scarlet Lettuce (RSL, line NFR-S-4).

<p>Diet-induced obese mice were given daily oral administrations of RSL, water (vehicle), or Metformin (<i>n</i> = 8, except Metformin group, <i>n</i> = 4). On day 8 of treatment, mice were fasted for 4 h, given 0.7 U insulin i.p. injection and blood glucose was recorded at indicated intervals. <b>A</b> Mean blood glucose (mg/dL) across time. <b>B</b> Mean change in blood glucose across time. <b>C</b> Area above the curve of the change in blood glucose across time. Data are presented as the mean ± SE. Significant differences vs vehicle control (* <i>p</i><0.05, ** <i>p</i><0.01, *** <i>p</i><0.001).</p

Rutgers Scarlet Lettuce regeneration media.

<p>Base medium: Murashige and Skoog basal medium with 3% sucrose and 0.7% agar.</p