The power of model-to-crop translation illustrated by reducing seed loss from pod shatter in oilseed rape

Abstract

In the 1980s, plant scientists descended on a small weed Arabidopsis thaliana (thale cress) and developed it into a powerful model system to study plant biology. The massive advances in genetics and genomics since then has allowed us to obtain incredibly detailed knowledge on specific biological processes of Arabidopsis growth and development, its genome sequence and the function of many of the individual genes. This wealth of information provides immense potential for translation into crops to improve their performance and address issues of global importance such as food security. Here we describe how fundamental insight into the genetic mechanism by which seed dispersal occurs in members of the Brassicaceae family can be exploited to reduce seed loss in oilseed rape (Brassica napus). We demonstrate that by exploiting data on gene function in model species, it is possible to adjust the pod-opening process in oilseed rape thereby significantly increasing yield. Specifically, we identified mutations in multiple paralogues of the INDEHISCENT and GA4 genes in B. napus and have overcome genetic redundancy by combining mutant alleles. Finally, we present novel software for the analysis of pod shatter data that is applicable to any crop for which seed dispersal is a serious problem. These findings highlight the tremendous potential of fundamental research in guiding strategies for crop improvement.KeymessageElucidation of key regulators in Arabidopsis fruit patterning has facilitated knowledge-translation into crop species to address yield loss caused by premature seed dispersal (pod shatter).

Genetic and Physiological Aspects of Silique Shattering in Rapeseed and Mustard

“…Pectin remains abundant in these areas, due to which carpel wall remains flexible even in desiccation and do not create same type of tension reducing shattering. Elongation in Brassicaceae fruits takes place within the development of specialized tissues, such as, valve margins at the replum borders (which are involved in the fruit dehiscence), valves (siliqua walls), and a central replum (Stephenson et al, 2019). Silique shattering resistance may relate more to tissue-specific anatomy and physiology of dehiscence zone and its surrounding area.…”

“…In silique shattering mainly three factors are involved: first, the weakening of cell walls in specified regions of dehiscence zone, second, the external surrounding tissues force, and third, the siliqua is exposed to the environment, which lead to shattering on desiccation stage (Meakin and Roberts, 1990a;Spence et al, 1996). The valve margins are composed of a separation layer and a lignified layer of distinct cell types (Stephenson et al, 2019). During fruit maturity, cells in the valve margins facilitate fruit opening by secreting polygalacturonase enzymes that degrade the rich-pectin separating layer (Petersen et al, 1996;Spence et al, 1996;Degan et al, 2001;Ogawa et al, 2009).…”