Rice lipases: a conundrum in rice bran stabilization: a review on their impact and biotechnological interventions

Abstract

Rice is a primary food and is one of the most important constituents of diets all around the world. Rice bran is a valuable component of rice, containing many oil-soluble vitamins, minerals, and oil. It is known for its ability to improve the economic value of rice. Further, it contains substantial quantities of minerals like potassium, calcium, magnesium, iron and antioxidants like tocopherols, tocotrienols, and γ-oryzanol, indicating that rice bran can be utilized effectively against several life-threatening disorders. It is difficult to fully utilize the necessary nutrients due to the presence of lipases in rice bran. These lipases break down lipids, specifically Triacylglycerol, into free fatty acids and glycerol. This review discusses physicochemical properties, mechanism of action, distribution, and activity of lipases in various components of rice seeds. The phylogenetic and gene expression analysis helped to understand the differential expression pattern of lipase genes at different growth phases of rice plant. Further, this review discusses various genetic and biotechnological approaches to decrease lipase activity in rice and other plants, which could potentially prevent the degradation of bran oil. The goal is to establish whether lipases are a major contributor to this issue and to develop rice varieties with improved bran stability. This information sets the stage for upcoming molecular research in this area.

Supplementary information: The online version contains supplementary material available at 10.1007/s12298-023-01343-3.

Keywords: Gene expression; Lipase; Oryza sativa; Rice bran.

Fig. 1

Schematic representation of hydrolytic and oxidative deterioration of rice bran oil, and different stabilization approaches

Fig. 2

The phylogenetic tree for selected lipases was constructed using protein sequences MEGA 7.0 software using the Maximum-likelihood method. The lipases marked with * are expressed in rice bran

Fig. 3

Heatmap showing spatio-temporal expression pattern of lipase genes using expression data from Genevestigator tool