Development of Taurine-CONTAINING PLANT seed

Aquafeed producers are turning to plant-based protein as a partial replacement for fishmeal. The problem is that plant-based protein lacks taurine (Tau), which is required for the normal development and growth of some types of fish and shellfish. One solution is to supplement plant-based aquafeed with synthetic Tau, which is manufactured in China from processes that use carcinogenic and hazardous substances. Plant Sensory Systems (PSS) has developed a technology, the Enhanced-Nutrition (EN) technology, which provides a more sustainable, cost-effective solution whereby plants with the EN technology synthesize and accumulate Tau.

Tau can be synthesized from cysteine (Cys) through the activities of two enzymes: Cys dioxygenase (CDO) and sulfinoalanine decarboxylase (SAD). The genes and proteins for Tau synthesis do not exist in higher plants. PSS used a molecular approach to move the CDO and SAD genes (EN technology) under the control of a constitutive promoter into the model plant Arabidopsis with the aim of producing Tau in plants. As a control, an empty vector (EVC) with no gene cassette was used. To determine whether Tau accumulated in the EN plants, free amino acids were extracted from the leaves of the EN and EVC plants and evaluated using high-performance liquid chromatography (HPLC). The 25 EN lines had Tau levels ranging from 0.05% to 0.33% dry weight. None of the 10 EVC lines had measurable Tau. The next question that was addressed was whether Tau production could be directed into the seeds. The EN technology under the control of a seed-specific promoter was introduced into Arabidopsis. The free amino acids of the EN and EVC seeds were analyzed and compared. The 9 EN lines had Tau levels ranging from 0.05% to 0.69% dry seed weight. None of the 5 EVC lines had measurable levels of Tau in the seeds.

PSS has transferred the EN technology under the control of a seed-specific promoter into soybean and the plants are currently growing in the greenhouse. Seeds from the EN lines should be harvested and analyzed in time for discussion at this venue.