ABSTRACT
The FRUITFULL (FUL) gene belongs to the AP1/ FUL subfamily of the plant MADS-box family and has functions in regulating flowering time, floral meristem differentiation and fruit development. PfFUL gene sequence was derived from the perilla transcriptome data, and the basic physicochemical properties of PfFUL were analyzed by bioinformatics methods. Evolutionary relationships of PfFUL with other species of FUL were analyzed by phylogenetic tree. Plant expression vector 35S::PfFUL was constructed and used to transform wild type Col-0 and mutant ful-7 Arabidopsis to obtain overexpression 35S::PfFUL/ Col-0 and complemented mutation 35S::PfFUL / ful-7 plants respectively. Comparative phenotypic analysis was performed to preliminarily clarify the function of PfFUL gene in plant flowering and fruit development. The functions of the PfFUL gene during flowering and angular fruit development of the plants were initially clarified. The CDS of PfFUL gene is 738 bp and encodes 245 amino acids. Phylogenetic tree showed that the perilla PfFUL was closely related to Solanum lycopersicum, Salvia splendens and Salvia hispanica, but far related to Arabidopsis thaliana, Nicotiana tabacum and Vitis vinifera. Compared to Col-0 and ful-7, the transgenic plants showed early flowering (P0. 05), and the amount of wrinkled seed was significantly reduced (P<0. 01). In addition, phenotypic observations revealed that the transgenic plants also exhibited increased internode length and narrowed and curled cauline leaves. In conclusion, this study confirmed that the PfFUL gene regulates early flowering and fruit development in plants and participates in nutritional growth.
ABSTRACT
ω-3-Fatty acid desaturase 8 (FAD8), as a dehydrogenase enzyme, plays a key role in the transformation of saturated fatty acids into unsaturated fatty acids, which is helpful to enhance the freezing tolerance of plants. However, it remains unclear whether the expression level of FAD8 in Perilla frutescens is regulated by low temperature. Based on transcriptome data, the FAD8 gene was cloned, characterized and then successfully expressed in tobacco Nicotiana tabacum. The gene was designated as PfFAD8 and has a full-length coding sequence of 1 317 bp coding for 438 amino acids with a predicted molecular weight of 50 kD and a theoretical isoelectric point of 9. 13. Our research indicated that the expression of PfFAD8 in Perilla frutescens was increased under the freezing stress. To further confirm this result, a 35S::PfFAD8 vector were constructed and transformed into N. tabacum by Agrobacterium tumefaciens-mediated transformation. Transgenic tobacco leaves that over-expressed the PfFAD8 gene exhibited significantly higher unsaturated fatty acids (UFA) such as linoleic (C18:2) and palmitic acid (C16:0) content and advanced freezing tolerance. Moreover, PfFAD8 overexpression in transgenic tobacco leaves increases malondialdehyde (MDA) and proline (PRO) content, and enhances defense enzymes activities of superoxide dismutase (SOD) and catalase (CAT) to some extent under the cold condition, which might prevent the decline of UFA. Taken together, PfFAD8 overexpression in Perilla frutescens might be involved in the desaturation process of lipids leading to increased membrane stability and/ or induction of other genes related to freezing tolerance by octadecanoid pathway or lipid peroxidation products. Thus, PfFAD8 overexpression could be useful in the production of freeze-tolerant varieties of N. tabacum.