10. CONCLUSIONS AND OUTLOOK
With global climate change, increasing temperature has an enormous impact on crop productivity from seedling to mature stages. Climate-smart crops will benefit from a better understanding of high temperature-associated processes. Although our knowledge on these processes has increased a lot in crops, most of the regulatory mechanisms associated with high temperature have been explored in the model plant Arabidopsis and are still elusive in many crops. While in some cases the knowledge gained from Arabidopsis can be translated to crops, there are also many unique aspects to crops. For example, with respect to high temperature-regulated growth it is not clear if the same cooling role from dicots can be assigned to monocot crop plants. This warrants exploring high temperature-related mechanisms directly in the relevant crop.
Understanding the molecular mechanism of how early developmental delay is regulated is an important consideration, especially given that unseasonal warm weather will disrupt vernalization significantly affecting flowering and subsequent grain production in winter crops. For example, the slow, winter-long upregulation of VERNALIZATION INSENSITIVE 3 (VIN3 ) through NTL8 in Arabidopsis , provides – in addition to direct thermosensing mechanisms – a long-term biological sensing of naturally fluctuating temperatures (Zhao, Antoniou-Kourounioti, Calder, Dean, & Howard, 2020).
In addition, crop yield and quality are affected by increased respiration caused by warmer night temperature, which is likely to occur in the near future. Understanding the molecular mechanisms underlying organ sterility at high temperature is an essential countermeasure for global warming. Given the complexity of high temperature responses (growth stages, different organs, time of day, multiple sensing mechanisms, etc), it is extremely difficult to capture this in breeding approaches. Dissection of the molecular responses that occur under warm (night-time) temperatures will therefore benefit from a multi-disciplinary approach that includes physiology, developmental biology and modelling.