Overexpressing Arabidopsis KNAT1 gene in Celosia plumosus L. causes modification of plant morphology

Abstract

Celosia plumosus L. is one of the most common gardening plants worldwide. The C. plumosus L. transformation system established by other research team should be useful for modifying physiological, medicinal, and horticultural traits. Though morphological modification of C. plumosus L. would be critical in terms of its commercial value, few attempts have been reported until now. In modification of gardening plants, many potentially useful genes that are involved in the pathways associated with flower and plant morphology have been cloned. Transcription factors regulating plant development and biosynthetic or regulatory genes involved in plant hormones are common candidates. KNAT1, isolated from Arabidopsis, is a knotted1-like homeobox (knox), and it is expressed in the shoot apical meristem and not in determinate organs. Previous reports have indicated that ectopic expression of KNAT1 in Arabidopsis changes simple leaves into lobed leaves or rumpled leaves. Therefore, this transcription factor might regulate plant morphology. In this work, we constructed the binary vector pBIN-pMD-18T, which contained the GFP and KNAT1 coding sequence, and transformed them into C. plumosus L. plants by Agrobacterium tumefaciens. Our results show that the KNAT1-GFP fusion protein was selectively located in the nucleus of roots and leaves, consistent with a potential function as transcription factor reported by other research teams. We observed that some 35S:KNAT1-GFP plants display lobed or rumpled leaves, partite leaves. Moreover, overall plant morphology was altered in extreme phenotype category, i.e., dwarfed. Together, these morphological modifications of C. plumosus L. can have potential practical applications.