Luis Pérez-Moreno

First Report of Leek yellow stripe virus in Garlic in the State of Guanajuato, Mexico

Garlic (Allium sativum L.) can be affected by a virus complex (1) consisting of two potyviruses, Onion yellow dwarf virus (OYDV) and Leek yellow stripe virus (LYSV), and two carlaviruses, Garlic common latent virus (GCLV) and Shallot latent virus (SLV) (1). To identify the components of the virus complex that could be present in garlic plants in Guanajuato State, which is the second largest garlic producer in the country and where presumptive viral symptoms were initially observed in December 2004, a survey was carried out in six locations: San Miguel de Allende and San Luis de la Paz in northern Guanajuato; Irapuato and Villagrán in the central region; and Salamanca and Valle de Santiago in the southern part of the state. Enzyme-linked immunosorbent assay (ELISA) was carried out to detect LYSV, OYDV, GCLV, and SLV in 195 garlic leaf samples collected during January 2005 from plants with leaf yellow stripe, mosaic, enation, deformation, or dwarfism symptoms. A set of primers, previously reported and specific to the coat protein cistron of LYSV (1), were synthesized and used in a reverse transcriptase-polymerase chain reaction (RT-PCR). The amplified product (1,020 nucleotides) was cloned into plasmid pGEM T-Easy (Promega, Madison, WI) and sequenced (Gen-bank Accession No. DQ841554). Sequence analysis showed that the cloned DNA fragment shared 97% similarity with the coat protein cistron of LYSV isolate no. 3 from Okinawa (GenBank Accession No. AB194632). The fragment was then radioactively labelled and used as a probe in the RNA blot analysis of all samples to confirm the ELISA results of LYSV. Of the 195 samples, 64 tested positive by RNA blot analysis. Forty-one of these were also positive by ELISA for LYSV. Preliminary, positive ELISA results were also obtained for OYDV, GCLV and SLV. To our knowledge, this is the first report of LYSV in the State of Guanajuato and in Mexico. The correct identification of viruses present in garlic will help to use the appropriate strategies to reduce viral incidence in this garlic-producing region. Reference: (1) T. V. M. Fajardo et al. Fitopatol. Bras. 26:619, 2001.

Characterization and Identification of Cryptic Biopeptides in Carya illinoinensis (Wangenh K. Koch) Storage Proteins

The objective of this research was to identify and characterize the encoded peptides present in nut storage proteins of Carya illinoinensis. It was found, through in silico prediction, proteomic analysis, and MS spectrometry, that bioactive peptides were mainly found in albumin and glutelin fractions. Glutelin was the major fraction with ~53% of the nut storage proteins containing at least 21 peptides with different putative biological activities, including antihypertensives, antioxidants, immunomodulators, protease inhibitors, and inhibitors of cell cycle progression in cancer cells. Data showed that using 50 μg/mL tryptic digests of enriched peptides obtained from nut glutelins is able to induce up to 19% of apoptosis in both HeLa and CasKi cervical cancer cells. To our knowledge, this is the first report that shows the potential value of the nut-encoded peptides to be considered as adjuvants in cancer therapies.

Air Layering and Tiny-Air Layering Techniques for Mesquite [Prosopis laevigata (H. B. ex Willd.) Johnst. M. C.] Tree Propagation

Prosopis laevigata is commonly known in Mexico as mesquite, and it is mostly found in the Central Mexican States. Mesquite has been driven to scarcity because the local population has used it for different purposes. Therefore, efficient, inexpensive, and reliable propagation methods are an aim to preserve and increase the mesquite resources. Air layering (treatment applied to young 1–1.2 m-long and 1.0–1.5.0 cm-wide branches) and tiny-air layering (applied to young 25–30 cm-long and 0.3–0.5 cm-wide branches) were investigated as asexual mesquite propagation methods. IBA (100, 250, and 500 mg l−1); NAA (50, 100, and 250 mg l−1); IAA (100, 250, and 500 mg l−1); and 2,4-D (100 and 1000 mg l−1) were used for the air layering method, whereas for the tiny-air layering protocol IBA (0.1, 0.3, 1.0, 3.0, 5.0, and 10.0 mg l−1) alone or combined with Chrysal were utilized. The highest response (90%) of air layerings was obtained with 500 mg l−1 IBA, having an average number of 1,785 roots per layering. For the tiny-air layering method, the best treatment was 3.0 mg l−1 IBA + Chrysal, which induced 90% of rooting, with an average number of 31.8 roots per layering.