Introduction
Climate change is increasingly threatening global food security (Lesk et al., 2022). Many regions have already witnessed significant yield losses caused by shifting temperatures and changing weather patterns. These losses are projected to worsen in the future (Tigchelaar et al., 2018, Fu et al., 2023). To ensure the stability of crop production systems, climate-aware strategies should be prioritized in breeding and agronomy (Hickey et al., 2019, Zhao et al., 2022). As a first step, a solid understanding of how climate change affects crop performance and of the genetic mechanisms underlying crop responses is thus essential before developing efficient and effective strategies in breeding and agronomic practices. When combined with innovative technologies, these strategies are expected to play a central role in addressing the challenge of crop adaptability to future climates.
Phenotypic plasticity, or the ability to alter performance in response to environmental conditions, is a fundamental characteristic of plants, including crops(Pigliucci et al., 2006), that enables them to thrive in diverse environments (Bonamour et al., 2019, Xue and Leibler, 2018). To harness this mechanism to enhance crop performance in changing environments, numerous studies have investigated the molecular basis of phenotypic plasticity across various traits, species, and environments (Liu et al., 2020, Kusmec et al., 2017). Genes that underlie phenotypic plasticity have been identified, and their effects have been shown to be dynamic across different environments (Des Marais et al., 2013, Li et al., 2018). Moreover, environmental factors that interact with genes to determine the overt phenotypes have been examined using algorithms such as Critical Environmental Regressor through Informed Search (CERIS) (Li et al., 2021, Li et al., 2022). Progress has also been made in determining the developmental patterns behind phenotypic plasticity (Mu et al., 2022). While these findings have expanded our understanding of phenotypic plasticity, it is crucial to use this knowledge to streamline strategies for helping crops adjust to current and future climate change.
Brassica napus (B. napus ) is a valuable crop in which phenotypic plasticity can be explored in the context of climate change. Compared to other seed crops, B. napus is less tolerant to water deficit and high temperature, highlighting the significant roles of rainfall and temperature as climate change indicators for B. napus (Vernon, 2006). Despite being predominantly grown in high rainfall areas with long growing seasons, B. napus has shown adaptability to low rainfall zones through the release of short season cultivars (Si and Walton, 2004). This geographical and seasonal adaptation highlights B. napus as an exceptional model crop for studying phenotypic plasticity and applications to adaptation strategies. Seed oil content (SOC) is a crucial trait in B. napus , influenced by both genetic and environmental factors (Tan et al., 2022, Tan et al., 2011, Baud and Lepiniec, 2010, Gunasekera et al., 2006, Han et al., 2022). Previous studies have suggested that SOC ofB. napus can be improved via traditional breeding and biotechnological approaches. However, integrative approaches that maximize SOC under future climate variability are lacking.
Here, we investigated the environmental indices and genetic basis behind phenotypic plasticity and propose an approach to facilitate crop breeding and agronomic practices in the face of climate change. In contrast to previous studies of phenotypic plasticity, we harnessed phenotypic plasticity to select optimal planting dates and identify adaptive genotypes to achieve the highest SOC for current and future environmental conditions. To this end, we used a diversity panel of 505B. napus inbred lines and conducted multi-environment trials in sites with contrasting weather patterns. Our study presents a systematic framework for determining the factors contributing to phenotypic plasticity, which can help to prepare for the consequences of climate change on agriculture.