Rice proteins that shrink grains identified as breeding target
Wu H, Sun X, Wang X, Xie C, Lv Y
Crop Improvement
The rice on your dinner plate could get plumper and more abundant if breeders tweak this newly found molecular brake, and the same protein-degradation trick likely applies to other grain crops in your garden or on your farm.
Rice plants make a protein called DEP2 that helps grains grow bigger, but two other proteins, SINA3 and SINA5, act like garbage collectors that tag DEP2 for destruction, keeping grain size in check. When scientists knocked out SINA3 and SINA5, DEP2 stuck around longer and the rice grains grew noticeably larger and heavier. It's a tidy example of how plants use molecular on-off switches to fine-tune something as important as seed size.
Key Findings
SINA3 and SINA5 physically bind DEP2 through its coiled-coil domain and add K48-linked ubiquitin chains that mark it for proteasomal breakdown
Six specific lysine residues on DEP2 (K399, K722, K746, K958, K962, K1344) are required for this degradation tag
Knocking out SINA3 and/or SINA5 increased grain size and 1000-grain weight without affecting other agronomic traits, while overexpressing either gene reduced grain size
chevron_right Technical Summary
Scientists discovered two proteins in rice that act like a dimmer switch on grain size, tagging a growth-promoting protein for destruction. Removing these switches makes rice grains bigger and heavier, offering a new way to boost yield without hurting other plant traits.
Abstract Preview
Original paper
The E3 Ubiquitin Ligases SINA3 and SINA5 Control DEP2 Ubiquitination and Proteasomal Degradation to Regulate Grain Size and Weight in Rice.
Grain size is a critical agronomic trait, yet the molecular mechanisms governing its determination in crops remain incompletely understood. While recent studies revealed that OsRING80 facilitates D...
open_in_new Read full abstractAbstract copyright held by the original publisher.
Species Mentioned
Was this useful?
Want to tell us more? (optional)
Thanks for the note!
Something went wrong — please try again.
Too many submissions. Try again in an hour.
Gene editing removes 97% of celiac-triggering proteins from bread wheat
It could mean that people with celiac disease — roughly 1 in 100 worldwide — may one day safely eat bread made from real wheat, without sacrificing the taste...
Rice is a cereal grain and in its domesticated form is the staple food of over half of the world's population, particularly in Asia and Africa. Rice is the seed of the grass species Oryza sativa —or, much less commonly, Oryza glaberrima. Asian rice was domesticated in China some 13,500 to 8,200 y...