The influence of abscisic acid on the ethylene biosynthesis pathway in the functioning of the flower abscission zone in Lupinus luteus.
Flower abscission is a highly regulated developmental process activated in response to exogenous (e.g. changing environmental conditions) and endogenous stimuli (e.g. phytohormones). Ethylene (ET) and abscisic acid (ABA) are very effective stimulators of flower abortion in Lupinus luteus, which is a widely cultivated species in Poland, Australia and Mediterranean countries. In this paper, we show that artificial activation of abscission by flower removal caused an accumulation of ABA in the abscission zone (AZ). Moreover, the blocking of that phytohormone's biosynthesis by NDGA (nordihydroguaiaretic acid) decreased the number of abscised flowers. However, the application of NBD - an inhibitor of ET action - reversed the stimulatory effect of ABA on flower abscission, indicating that ABA itself is not sufficient to turn on the organ separation. Our analysis revealed that exogenous ABA significantly accelerated the transcriptional activity of the ET biosynthesis genes ACC synthase (LlACS) and oxidase (LlACO), and moreover, strongly increased the level of 1-aminocyclopropane-1-carboxylic acid (ACC) - ET precursor, which was specifically localized within AZ cells. We cannot exclude the possibility that ABA mediates flower abscission processes by enhancing the ET biosynthesis rate. The findings of our study will contribute to the overall basic knowledge on the phytohormone-regulated generative organs abscission in L. luteus.
Chair of Plant Physiology and Biotechnology, Nicolaus Copernicus University, 1 Lwowska Street, 87-100 Toruń, Poland; Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University, 4 Wileńska Street, 87-100 Toruń, Poland. Electronic address: emwil@umk.pl.
Emilia
E
Wilmowicz
Chair of Plant Physiology and Biotechnology, Nicolaus Copernicus University, 1 Lwowska Street, 87-100 Toruń, Poland. Electronic address: kfrank@o2.pl.
Kamil
K
Frankowski
Chair of Plant Physiology and Biotechnology, Nicolaus Copernicus University, 1 Lwowska Street, 87-100 Toruń, Poland. Electronic address: kuckoa@poczta.onet.pl.
Agata
A
Kućko
Department of Cell Biology, Nicolaus Copernicus University, 1 Lwowska Street, 87-100 Toruń, Poland. Electronic address: shihan@poczta.onet.pl.
Michał
M
Świdziński
Department of Biochemistry, Cellular and Molecular Biology of Plants, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas (CSIC), Profesor Albareda 1, 18008, Granada, Spain. Electronic address: juandedios.alche@eez.csic.es.
Juan
J
de Dios Alché
Department of Animal Physiology, Nicolaus Copernicus University, 1 Lwowska Street, 87-100 Toruń, Poland. Electronic address: noann@umk.pl.
Anna
A
Nowakowska
Chair of Plant Physiology and Biotechnology, Nicolaus Copernicus University, 1 Lwowska Street, 87-100 Toruń, Poland. Electronic address: kopcew@umk.pl.
Jan
J
Kopcewicz
D000040:Abscisic Acid / Q000494:pharmacology*; D000598:Amino Acids, Cyclic / Q000378:metabolism; D053898:Biosynthetic Pathways / Q000187:drug effects* / Q000235:genetics; D005030:Ethylenes / Q000096:biosynthesis*; D035264:Flowers / Q000187:drug effects / Q000502:physiology*; D005455:Fluorescent Antibody Technique; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D031297:Lupinus / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D009637:Masoprocol / Q000494:pharmacology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects
D000598:Amino Acids, Cyclic; D005030:Ethylenes; D010940:Plant Proteins; C023863:1-aminocyclopropane-1-carboxylic acid; D000040:Abscisic Acid; D009637:Masoprocol; C036216:ethylene
Abscisic acid; Ethylene; Interactions; Lupinus luteus; Organ abscission