ABSTRACT
Somatic embryos (SE) of habanero pepper (Capsicum chinense Jacq.) represent persistent deformations in the shoot apical meristem (SAM), which inhibits their capacity to form organs and subsequently plants. In dicotyledonous plants, SAM is formed in the apex, between cotyledons and it plays a central role in postembryonic shoot organ formation. Based on the previous knowledge on the role of some families of gene in the formation, organization and maintenance of the SAM, the expression patterns of WUS, WOX2, NAM, STM, PIN1 and PIN7 genes were analysed, which would allow us to elucidate the possible implication of these genes in SAM deformations in the SE of C. chinense. The results show that the expression patterns of STM and PIN1 in the SE were completely opposite to the respective expression pattern obtained in zygotic embryos (ZE). Moreover, NAM and PIN7 showed an over accumulation of transcripts in SE, compared with ZE. This is the first time in the genus Capsicum that alterations in the expression pattern of key genes of the SE development are reported, as well as its possible implication in the persistent deformations of the SAM.
Subject(s)
Capsicum/genetics , Meristem/embryology , Meristem/genetics , Plant Proteins/genetics , Capsicum/embryology , Cotyledon/embryology , Cotyledon/genetics , Gene Expression Regulation, Plant , Homeodomain Proteins/metabolism , Meristem/growth & development , Microfilament Proteins/metabolism , NIMA-Interacting Peptidylprolyl Isomerase/metabolism , Plant Somatic Embryogenesis Techniques , Repressor Proteins/metabolismABSTRACT
The purpose of this work was to isolate and identify native bacteria from plants collected in the State of Yucatán, México with the ability to promote growth of chili pepper (Capsicum annuum L. cv Jalapeño). We identified nine bacterial isolates that belong to five species of Bacillus (i.e. Bacillus subtilis, B. flexus, B. cereus, B. megaterium and B. endophyticus) that produced indoleacetic acid (4.0-24.3 µg/mL) with solubilization index of 1.3-1.6. All the bacterial isolates were evaluated based on their ability to promote growth of chili pepper. Plants inoculated with B. subtilis ITC-N67 showed an increase in stem diameter and root volume, whereas inoculation with B. cereus ITC-BL18 increased the number of flower buds, fresh biomass of roots and total fresh biomass. Conversely, B. flexus ITC-P4 and B. flexus ITC-P22 showed deleterious effect on root volume and total biomass. In summary, our data showed that native B. cereus TC-BL18 and B. subtilis ITC-N67 have potential to be used as growth promoting microorganism for chili pepper, particularly in the state of Yucatán, México.
