Brassinosteroids

J. W. Mitchell, N. B. Mandava and others' 1970 publication in Nature, "Brassins-A New Family of Plant Hormones from Rape Pollen" announced the discovery of a new plant hormone, brassinolide, which would also mark the sixth and newest group of plant hormones, brassinosteroids. This monograph details the early research leading to the isolation and synthesis of the first brassinosteroid to current research in the field. The 50 years of brassinosteroid research can be separated in two parts; The first 25 years saw the innovation of different bioassays and isolation techniques while the last 25 years saw the investigation into brassinosteroids signaling, cross talk, stress response, and agricultural application. Since the discovery of brassinolide, there have now been 62 brassinosteroids identified through international research efforts. Several of these have been targeted for agricultural use with patents in many countries. Homobrassinolide is one such brassinosteroid that helps improve crop yield and fruit sweetness while conferring stress resistance. This monograph is the first to fully encompass the story of brassinosteroids.




Progress in the First 25 Years

Discovery of Brassins 1970 - Mitchell, Mandava, and others (Nature article)

Screening of Various Kinds of Pollen

Brassins - Field trials in Brazil and the USA

Discovery of Brassinolide

Detection of active ingredient by Bean Second-Internode Bioassay

Isolation from Rapeseed (Brassica napus L.) Pollen




Development of Laboratory Scale Purification Method

Pilot-Plant Extraction of Pollen

Identification of Brassinolide

Synthesis of Brassinolide

Structure-Activity of Brassinolide Analogs

Synthesis of Brassinolide from sterol isolated from oysters

Other Synthetic Methods for Brassinolide

Development of Other Bioassays -

Screening of Brassinosteroids using Various Bioassays

Development of Sensitive Analytical Methods for Detection of Brassinosteroids




Isolation of Other Brassinosteroids from Various Plant Sources

Synthesis of Other Brassinosteroids

Selection of three Brassinosteroids based on Bioassays

Metabolism of Brassinosteroids

Biosynthesis of Brassinosteroids




Progress in the Second 25 Years

Brassinosteroid Signaling

Brassinosteroid Crosstalk

Physiological Responses

Senescence

Stress Responses

Pathogen Attack

Gene Regulation

Signal Transduction

Metabolism of Brassinosteroids (cont.)

Brassinosteroid Bio efficacy

Agricultural Uses

Mode of Action and Economic Benefits

Field Trials