Hironori Itoh, Hiroto Yamashita, Kaede C. Wada, and Jun-ichi Yonemaru

PNAS, May 13, 2024; 121 (21) e2316497121

https://doi.org/10.1073/pnas.2316497121

Significance

Developing climate-resilient crops is important for sustainable agriculture and maintaining food security. In this study, we simulated severe global warming in a customized growth chamber, revealing a significant advancement in rice life cycles and a notable reduction in grain quality in modern Japanese cultivars in a temperate region. While our evaluation is limited to certain temperate japonica cultivars, the results underscore the value of simulating less observable severe global warming environments for a comprehensive understanding of their impact on rice cultivation. Expanding this approach to diverse varieties and regions will offer a more realistic view of global warming’s impact on rice production.

Abstract

Decreased production of crops due to climate change has been predicted scientifically. While climate-resilient crops are necessary to ensure food security and support sustainable agriculture, predicting crop growth under future global warming is challenging. Therefore, we aimed to assess the impact of realistic global warming conditions on rice cultivation. We developed a crop evaluation platform, the agro-environment (AE) emulator, which generates diverse environments by implementing the complexity of natural environmental fluctuations in customized, fully artificial lighting growth chambers. We confirmed that the environmental responsiveness of rice obtained in the fluctuation of artificial environments is similar to those exhibited in natural environments by validating our AE emulator using publicly available meteorological data from multiple years at the same location and multiple locations in the same year. Based on the representative concentration pathway, real-time emulation of severe global warming unveiled dramatic advances in the rice life cycle, accompanied by a 35% decrease in grain yield and an 85% increase in quality deterioration, which is higher than the recently reported projections. The transcriptome dynamism showed that increasing temperature and CO₂ concentrations synergistically changed the expression of various genes and strengthened the induction of flowering, heat stress adaptation, and CO₂ response genes. The predicted severe global warming greatly alters rice environmental adaptability and negatively impacts rice production. Our findings offer innovative applications of artificial environments and insights for enhancing varietal potential and cultivation methods in the future.

See https://www.pnas.org/doi/10.1073/pnas.2316497121