Biology subjects

Esfandiari, A.

Publications and source records attributed to Esfandiari, A..

2 recordsLinked to original sources

bioRxiv2024

Chromosome-level Genome Assembly and Annotation of Petunia hybrida

Petunia hybrida is the worlds most popular garden plant and is regarded as a supermodel for studying the biology associated with the Asterid clade, the largest of the two major groups of flowering plants. Unlike other Solanaceae, petunia has a base chromosome number of seven, not 12. This along with recombination suppression has previously hindered efforts to assemble its genome to chromosome level. Here we achieve a chromosome-level assembly for P. hybrida using a combination of short-read and long-read sequencing, optical mapping (Bionano) and Hi-C technologies. The resulting assembly spans 1253.6 Mb with a BUSCO score of 99.8%. A total of 35,089 genes were predicted and of those 29,655 were functionally annotated. Syntenic regions between petunia, tomato and pepper were identified, highlighting rearrangements that have occurred since their divergence indicating that the 12 chromosomes of Solanaceae did not originate from whole genome duplication of an ancestral species with seven chromosomes like petunia. This chromosome-level assembly will significantly enhance trait mapping efficiency in petunia and serve as a valuable resource for functional genomic studies in this key plant model.

genomics↗

bioRxiv2020

Strigolactone defective mutants of Arabidopsis exhibit delayed sepal senescence

Flower sepals are critical for flower development and vary greatly in lifespan depending on their function postpollination. However, very little is known on what controls sepal longevity. Using a sepal senescence mutant screen, we directly connected strigolactones (SL) with sepal longevity. We identified two Arabidopsis mutants that harbour novel mutations in the SL biosynthetic gene MORE AXILLARY GROWTH1 (MAX1) and receptor DWARF14 (AtD14). The mutation in AtD14 caused a substitution of the catalytic Ser-97 to Phe in the enzyme active site. The lesion in MAX1 changed a highly conserved Gly-469 to Arg in the haem-iron ligand signature of the cytochrome P450 protein, which caused loss-of-function of MAX1. nCounter-based transcriptional analysis suggested an interaction between SL and sugar signalling in controlling dark-induced inflorescence senescence. The results uncover an important function for SL in regulating floral organ senescence in addition to its other diverse functions in plant development and stress response. One-sentence summaryTwo novel mutants in the strigolactone pathway demonstrate a role for the hormone in sepal senescence, and transcriptional analysis highlights interaction between strigolactones and sugar signalling.

plant biology↗