The regulation of grain weight in wheat

Wheat (Triticum aestivum L., AABBDD) is one of the world's most extensively cultivated crops, furnishing vital nutrients and energy for human consumption. Wheat seeds are the primary sustenance source. Given the mounting global population and dwindling arable land, enhancing wheat grain yield remains a concern for mankind. A pivotal agronomic trait influencing grain yield is grain weight, which is predominantly contingent on seed size and endosperm components and is regulated by complex and precise molecular networks. Endogenous factors, such as transcriptional and post-translational regulators, exert pivotal influence over seed development. Notably, starch is the main storage component of wheat endosperm, and the starch synthesis-related genes exert an important effect on grain weight. Prior reviews on wheat grain traits have mostly focused on the regulation of grain size, and the contents of such reviews are almost entirely written based on the regulatory network of rice seed size. Although many regulatory mechanisms for various traits are similar in rice and wheat, there are lots of differences in wheat due to its vast and intricate genome. An all-encompassing panorama of the grain weight regulatory network has not yet been comprehensive. This review summarizes the catalog of reported genes, discusses the emerging molecular mechanisms, and delves into regulatory networks to foster a more holistic understanding of the intricate regulation of wheat seed weight.