ABSTRACT
Polar transport of the phytohormone auxin is a well-known physiological phenomenon recorded in different extant plant groups including bryophytes and pteridophytes. Earlier, this phenomenon has been recorded in an Upper Devonian (375 million-year) arborescent progymnosperm, Archaeopteris. Since then further record of such occurrence of polar auxin flow is known especially from younger horizons. The present investigation records the evidence of such disrupted polar auxin flow in the form of auxin whirlpool in fossil woods of Tracheidoxyl, Ailanthoxylon indicum and Calophylloxylon sp. from the Middle Oxfordian (Jurassic) to Neogene (Mio-Pliocene) sediments of India.
Acknowledgments
UGC–CAS (Phase VII), Department of Botany, University of Calcutta, is thankfully acknowledged for necessary support.
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No potential conflict of interest was reported by the authors.
Additional information
Notes on contributors
Ashalata D’Rozario
Ashalata D’Rozario is a retired Associate Professor and researcher at the Department of Botany, University of Calcutta, India. She studied the literatures, worked out the specimen and carried out the anatomical and comparative study of fossil wood specimen of the gymnosperm wood and prepared the manuscript.
Illora Sen
Illora Sen is an Assistant Professor at Department of Botany, Shri Shikshayatan College and researcher at the Department of Botany, University of Calcutta, India. She prepared the sample and carried out the anatomical and comparative study of fossil wood specimen of Calophylloxylon sp. and helped in writing the manuscript.
Dipak Kumar Paruya
Dipak Kumar Paruya is an Assistant Teacher in Tiljala High School and researcher at the Department of Botany, University of Calcutta, India. He worked out the specimen and carried out the anatomical and comparative study of fossil wood specimen of Ailanthoxylon indicum and helped in the preparation of the manuscript.
Anupam Guha
Anupam Guha is an assistant professor at Department of Botany, Women’s College, Agartala, Vishal Verma, teacher at Bakaner Govt. High School, Dhar District, M.P., Sharmistha Paul, Department of Earth Sciences, IIEST, Shibpur, Howrah, Tapas Kumar Gangopadhyay Department of Earth Sciences, IIEST, Shibpur, Howrah collected the fossil woods and helped in writing the manuscript.
Arindam Roy
Arindam Roy (GSI, Kolkata) and Subhronil Mondal (Department of Geology, University of Calcutta, India) collected the fossil gymnosperm wood and gave relevant stratigraphic information of the fossil sample.
Subir Bera
Subir Bera is a researcher and Professor at the Department of Botany, University of Calcutta, India. He guided the entire course of this research, scrutinized and refined the manuscript as a corresponding author.