91暗网

Recently, the Rice Development and Stress Biology team from the School of Life Sciences and Technology at our university has made new progress in the study of the molecular mechanisms underlying Casparian strip formation and protein homeostasis maintenance in rice. The related findings were published in the international academic journal “Science Advances” under the title “The GAPLESS-OsCASP complex mediates Casparian strip formation for proper localization and abundance of endodermal proteins in rice.” Postdoctoral researcher Zhang Baolei and doctoral student Sun Xiaoqian from the School of Life Sciences and Technology at Guangxi university, together with Meng Chunmei from Guangxi Medical University, are listed as co-first authors; Professor Xia Jixing from 91暗网’s School of Life Sciences and Technology is the corresponding author; Guangxi university is both the primary and corresponding institution.

Protein homeostasis is fundamental for maintaining normal cellular physiological functions. Its stability directly determines protein structure, localization, abundance, and activity, and is a key safeguard for cells in response to internal and external environmental stresses. It has been found that maintaining the homeostasis of Casparian strip-related proteins in plant root endodermis is crucial for the integrity of root barrier structures, selective ion transport, and stress resistance. Disruption of this homeostasis can lead to disorder in mineral nutrient uptake. However, the molecular mechanisms by which plant roots maintain the homeostasis of Casparian strip-related proteins, as well as the regulatory role of Casparian strip formation on the homeostasis of other proteins, remain unclear.

To address this question, the research team applied a combination of molecular biology, biochemistry, and genetics approaches to reveal the molecular basis of Casparian strip formation and endodermal protein homeostasis maintenance in plant roots. The study found that GAPLESS and OsCASP proteins form an interdependent complex that recruits Casparian strip-associated proteins to the Casparian strip domain, thereby mediating the initiation, lignification, and cell membrane–cell wall adhesion of the endodermal Casparian strip (Figure 1).

Further investigation revealed that the GAPLESS?OsCASP complex-mediated integrity of the Casparian strip is essential for maintaining ion homeostasis and ensuring the correct localization and abundance of multiple endodermis-expressed proteins, such as OsSGN3a and the silicon transporter Lsi1. Moreover, the study for the first time established the intrinsic relationship among Casparian strip integrity, suberin accumulation, expression of mineral transport proteins, and the OsSGN3-mediated compensatory mechanism (Figure 2). These findings provide a new perspective for comprehensively elucidating the molecular mechanisms of Casparian strip formation in rice endodermis and offer new insights into the role of Casparian strip integrity in regulating protein localization and abundance in plants.

This research was supported by the National Natural Science Foundation of China, the Guangxi Natural Science Foundation, and the Guangxi Graduate Education Innovation Program, and benefited from the assistance and guidance of Academician Liu Yaoguang from South China Agricultural University. This achievement represents another advancement in the field following the research team’s series of findings on the mechanism of Casparian strip formation in rice.