Signaling mechanisms and biochemical pathways regulating pollen-stigma interaction, seed development and seedling growth in sunflower under salt stress

Abstract

Sunflower (Helianthus annuus L.) is one of the major oilseed crops cultivated world over for its high-quality oil rich in linoleic acid. It also has established applications in pharmaceutical and biotechnological industries, mainly through recombinant production of unique oil body (OB) membrane proteins-oleosins, which are used for producing a wide variety of vaccines, food products, cosmetics and nutraceuticals. The present review provides a critical analysis of the progress made in advancing our knowledge in sunflower biology, ranging from mechanisms of pollen-stigma interaction, seed development, physiology of seed germination and seedling growth under salt stress, and finally understanding the signaling routes associated with various biochemical pathways regulating seedling growth. Role of nitric oxide (NO) triggered post-translational modifications (PTMs), discovered in the recent past, have paved way for future research directions leading to further understanding of sunflower developmental physiology. Novel protocols recently developed to monitor temporal and spatial distributions of various biochemicals involved in above-stated developmental events in sunflower, will go a long way for similar applications in plant biology in future.

Keywords: Sunflower; seed development; seedling growth; signaling mechanisms.

Figure 1.

NO-modulated ethylene and SL biosynthesis and possible causes of their impact on lateral root formation

Figure 2.

Proposed model of fatty acid biosynthesis in sunflower achenes and modulation of its composition as a response to 120 mM NaCl

Figure 3.

An overview of differential expression pattern of NO, ROS, post-translational protein modifications (tyrosine nitration and S-nitrosylation) and organeller abundance in 2 d old salt-tolerant and sensitive seedlings in response to salt stress, NO donor and NO scavenger