Biomaterial Database

Strigolactones regulate sepal senescence in Arabidopsis. 2021

Xi Xu, and Rubina Jibran, and Yanting Wang, and Lemeng Dong, and Kristyna Flokova, and Azadeh Esfandiari, and Andrew R G McLachlan, and Axel Heiser, and Andrew J Sutherland-Smith, and David A Brummell, and Harro J Bouwmeester, and Paul P Dijkwel, and Donald A Hunter

Massey University, School of Fundamental Sciences, Palmerston North, New Zealand.

Flower sepals are critical for flower development and vary greatly in life span depending on their function post-pollination. Very little is known about what controls sepal longevity. Using a sepal senescence mutant screen, we identified two Arabidopsis mutants with delayed senescence directly connecting strigolactones with senescence regulation in a novel floral context that hitherto has not been explored. The mutations were in the strigolactone biosynthetic gene MORE AXILLARY GROWTH1 (MAX1) and in the strigolactone receptor gene DWARF14 (AtD14). The mutation in AtD14 changed the catalytic Ser97 to Phe in the enzyme active site, which is the first mutation of its kind in planta. The lesion in MAX1 was in the haem-iron ligand signature of the cytochrome P450 protein, converting the highly conserved Gly469 to Arg, which was shown in a transient expression assay to substantially inhibit the activity of MAX1. The two mutations highlighted the importance of strigolactone activity for driving to completion senescence initiated both developmentally and in response to carbon-limiting stress, as has been found for the more well-known senescence-associated regulators ethylene and abscisic acid. Analysis of transcript abundance in excised inflorescences during an extended night suggested an intricate relationship among sugar starvation, senescence, and strigolactone biosynthesis and signalling.

UI	MeSH Term	Description	Entries
D007783	Lactones	Cyclic esters of hydroxy carboxylic acids, containing a 1-oxacycloalkan-2-one structure. Large cyclic lactones of over a dozen atoms are MACROLIDES.	Lactone
D010937	Plant Growth Regulators	Any of the hormones produced naturally in plants and active in controlling growth and other functions. There are three primary classes: auxins, cytokinins, and gibberellins.	Phytohormone,Phytohormones,Plant Growth Regulator,Plant Hormone,Plant Hormones,Growth Regulators, Plant,Regulators, Plant Growth,Growth Regulator, Plant,Hormone, Plant,Hormones, Plant,Regulator, Plant Growth
D006575	Heterocyclic Compounds, 3-Ring	A class of heterocyclic compounds that include a three-ring fused structure. Both aromatic or non-aromatic ring structures are included in this category.	Fused Heterocyclic Compounds, Three-Ring,Heterocyclic Cpds, 3 Ring,Three Ring Heterocyclic Compounds,3-Ring Heterocyclic Compounds,Fused Heterocyclic Compounds, Three Ring,Heterocyclic Compounds, 3 Ring
D017360	Arabidopsis	A plant genus of the family BRASSICACEAE that contains ARABIDOPSIS PROTEINS and MADS DOMAIN PROTEINS. The species A. thaliana is used for experiments in classical plant genetics as well as molecular genetic studies in plant physiology, biochemistry, and development.	Arabidopsis thaliana,Cress, Mouse-ear,A. thaliana,A. thalianas,Arabidopses,Arabidopsis thalianas,Cress, Mouse ear,Cresses, Mouse-ear,Mouse-ear Cress,Mouse-ear Cresses,thaliana, A.,thaliana, Arabidopsis,thalianas, A.
D018506	Gene Expression Regulation, Plant	Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in plants.	Plant Gene Expression Regulation,Regulation of Gene Expression, Plant,Regulation, Gene Expression, Plant
D029681	Arabidopsis Proteins	Proteins that originate from plants species belonging to the genus ARABIDOPSIS. The most intensely studied species of Arabidopsis, Arabidopsis thaliana, is commonly used in laboratory experiments.	Arabidopsis thaliana Proteins,Thale Cress Proteins,Proteins, Arabidopsis thaliana,thaliana Proteins, Arabidopsis