ABSTRACT
GOLDEN2-LIKE (GLK) is a member of the myeloblastosis (MYB) family transcription factor and it plays an important role in the regulation of plastid development and stress tolerance. In this study, a gene named AhGLK1b was identified from a cultivated peanut showing down-regulation in response to low calcium with a complete open reading frame (ORF) of 1212 bp. The AhGLK1b has 99.26% and 96.28% sequence similarities with its orthologs in Arachis ipaensis and A. duranensis, respectively. In the peanut, the AhGLK1b was localized in the nucleus and demonstrated the highest expression in the leaf, followed by the embryo. Furthermore, the expression of AhGLK1b was induced significantly in response to a bacterial pathogen, Ralstonia solanacearum infection. Ectopic expression of AhGLK1b in Arabidopsis showed stronger resistance against important phytopathogenic fungi S. sclerotiorum. It also exhibited high resistance to infection of the bacterial pathogen Pst DC3000. AhGLK1b-expressing Arabidopsis induced defense-related genes including PR10 and Phox/Bem 1 (PBI), which are involved in multiple disease resistance. Taken together, the results suggest that AhGLK1b might be useful in providing dual resistance to fungal and bacterial pathogens as well as tolerance to abiotic stresses.
Subject(s)
Disease Resistance , Plant Proteins/genetics , Plants, Genetically Modified/genetics , Transcription Factors/genetics , Arabidopsis/genetics , Arabidopsis/microbiology , Arachis/genetics , Ascomycota/pathogenicity , Ectopic Gene Expression , Plant Proteins/metabolism , Plants, Genetically Modified/microbiology , Pseudomonas syringae/pathogenicity , Transcription Factors/metabolism , TransgenesABSTRACT
Genomic simple sequence repeat (SSR) markers were used to fingerprint and determine genetic similarity (GS) of the watermelon breeding lines, as well as the purity of their hybrid derivatives. Cluster analysis and Jaccard's distance coefficients using the unweighted pair group method with arithmetic mean (UPGMA) have classified these lines into three major groups. Notwithstanding,the genetic background of these lines is narrow as revealed by the restricted GS coefficients. Fifty-five sets of SSR markers were employed in this study. Fourteen of these markers were polymorphic between the breeding lines and were used for assessing hybrid purity. Cross-checking assay validated nine SSR markers as informative SSR markers for purity detection of these hybrids. To confirm the accuracy and efficiency of these markers, their derived PCR products were further sequenced, and ClSSR09643, ClSSR18153 and ClSSR01623 were selected as high-efficiency SSR markers. Interestingly, SSR markers ClSSR09643 and ClSSR18153 were broadly applied for purity detection of more than two different hybrids, while SSR marker ClSSR01623 behaved as a specific marker forpurity detection in this study. Genetic purity of six commercial watermelon hybrids was definitely evaluated using these SSR markers. Genetic purity of all tested hybrids exceeded 96% while the field purity was above 98%. Genetic purity test was an emergency for identifying off-types and selfed female in a lot of hybrid seeds. Here, we elucidated the potential of nine SSR markers including threewith higher breeding selection efficiency. We recommended them to seed company for purity improvement of watermelon commercial hybrid varieties.
