Professor Liu Huan's team from BGI Research, along with Professor Zhao Yu's team from Huazhong Agricultural University (HZAU) and Dr Lv Jun recently published a groundbreaking study titled "Comparative spatial transcriptomics reveals root dryland adaptation mechanism in rice and HMGB1 as a key regulator" in the prestigious international plant biology journal Molecular Plant.
The research team selected 16 genetically similar varieties of lowland paddy rice and upland rice. Using HZAU's advanced phenomics platform, researchers investigated the phenotypic changes in root length and thickness during the growth stages of upland rice and lowland paddy rice. The findings indicated that upland rice possesses longer roots and is thicker in diameter than lowland paddy rice. Despite having fewer crown roots, it displays enhanced drought resistance, suggesting the presence of distinct molecular regulatory mechanisms in its root system.
In response to these observed phenotypic disparities, the team constructed a dynamic gene expression atlas of root development using the Stereo-seq spatial transcriptomics technology.
Moreover, through genetic experimentation, the researchers confirmed that HMGB1, a transcriptional regulator of the HMGB family highly expressed in upland rice, plays a crucial role. Knocking out HMGB1 in rice led to the development of stronger and more drought-resistant roots.

Phenotype of HMGB1 transgenic mutants. [Photo/news.hzau.edu.cn]
This study not only unveils the molecular underpinnings of upland rice's adaptation to drought but also offers novel avenues for enhancing crop drought tolerance through genetic modifications.