Chinese Academy of Sciences Headquarters
A groundbreaking study has unveiled an innovative breeding strategy aimed at swiftly developing climate-smart crops. These crops demonstrate higher yields under standard conditions and significantly mitigate yield losses during heat stress, applicable to both staple grains and vegetable crops.
This pivotal research was released on December 13, highlighting the efforts of a team from the Institute of Genetics and Developmental Biology under the Chinese Academy of Sciences.
As we approach the year 2050, food production must increase by 60% to accommodate a projected global population of 10 billion. Current crop yields are inadequate and are anticipated to decline further due to the impacts of climate change.
An increase of 2 °C during the growing season can lead to yield reductions of 3% to 13%. To secure global food supplies and overcome existing breeding challenges, the development of “climate-smart” crops that deliver improved yields under both normal conditions and heat stress is critical.
The physiological dynamics of crop yield and quality are defined by the source-sink relationship. Source tissues, like leaves, produce photoassimilates, primarily carbohydrates such as sucrose. In contrast, sink tissues—fruits, seeds, and storage organs—are dependent on these photoassimilates for growth and development.
The cell wall invertase gene plays a vital role in regulating this source-sink interaction in plants. This gene encodes an enzyme responsible for converting sucrose from leaves into glucose and fructose within sink organs, essential for the growth of fruits and seeds while also determining fruit sweetness and rice grain quality.
Heat stress hampers cell wall invertase activity, disrupting the source-sink balance and leading to energy deficiencies in sink organs, which negatively impacts reproductive development and yields.
The research team developed a climate-responsive carbon partitioning optimization strategy, using targeted expression manipulation of cell wall invertase genes in fruit and cereal crops. By introducing a 10-bp heat-shock element into the promoters of these genes in elite rice and tomato varieties, the study enhanced carbon allocation to sink tissues under both controlled and field conditions.
Tests conducted across multiple locations and seasons demonstrated that the new strategy increased tomato yields by 14% to 47% under normal conditions. During heat stress periods, the method improved per-plot fruit yields by 26% to 33% compared to control groups, recovering up to 100% of yield losses attributed to heat stress. Additionally, the quality of the fruits, such as uniformity and sugar content, showed marked improvement.
Rice varieties enhanced by this strategy exhibited a yield increase of 7% to 13% under normal conditions and a remarkable 25% increase under heat stress. Up to 41% of potential grain yield losses from heat stress were also mitigated.
This efficient and adaptable breeding approach not only allows for rapid crop enhancement but also sets a precedent for the development of climate-smart crops through precise gene editing. Furthermore, this strategy has been successfully applied to other crops, including soybeans, wheat, and corn.
