Smith Brian E, Lu Chaofu
Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717-3150, USA.
Heliyon. 2024 Feb 19;10(4):e26678. doi: 10.1016/j.heliyon.2024.e26678. eCollection 2024 Feb 29.
Camelina ( L. Crantz) is a low-input oilseed crop with great potential in bioenergy and industrial oils. Improving tolerance to high temperatures is essential for camelina agronomic sustainability. Two genotypes, Suneson and Pryzeth, were exposed to a transient 14-day heat stress at 37 °C during the reproductive stages. Four cohorts of pods along the main stem, which were at different stages from fully developed pods (C1), young pods (C2), open flowers (C3) and flowering buds (C4) at the time of heat treatment, were examined for morphological and seed quality traits at maturity. The main stem length was shortened in both genotypes. Pods and seeds in all cohorts were negatively affected by heat, resulting in lower seed yield and reduced oil content. Seed size and seed weight had the greatest reduction in C1, pod size reduction was found the most in C3, and the number of fertile pods that contain at least one seed was reduced in C3 and C4. These results suggest that heat stress effects are developmental stage specific. Heat stress significantly reduced fertility during flowering and inhibited storage product biosynthesis and accumulation during seed filling which resulted in smaller and lighter seeds. Analyzing seed composition indicated that oil content decreased while protein content increased in seeds from heat treated plants. In addition, fatty acid composition was altered with the reduction of omega-3 α-linolenic acid and concomitantly increased omega-6 linoleic acid being the most significantly affected. Our results also revealed the different responses in the two genotypes examined, suggesting genetic variation in camelina germplasm which can be explored to improve heat tolerance. This study provides resources and guidance for future studies to understand genetic and physiological mechanisms of heat stress and to assist in improving the sustainability of camelina production facing climate change.
亚麻荠（L. Crantz）是一种低投入的油料作物，在生物能源和工业用油方面具有巨大潜力。提高对高温的耐受性对于亚麻荠的农艺可持续性至关重要。两个基因型Suneson和Pryzeth在生殖阶段经历了14天37°C的短暂热应激。沿着主茎的四组豆荚，在热处理时处于不同阶段，从完全成熟的豆荚（C1）、幼嫩豆荚（C2）、开放花朵（C3）到花芽（C4），在成熟时对其形态和种子质量性状进行了检查。两个基因型的主茎长度均缩短。所有组的豆荚和种子都受到热的负面影响，导致种子产量降低和含油量减少。种子大小和种子重量在C1中减少最多，豆荚大小在C3中减少最多，而在C3和C4中至少含有一粒种子的可育豆荚数量减少。这些结果表明热应激效应具有发育阶段特异性。热应激显著降低了开花期的育性，并抑制了种子充实期贮藏产物的生物合成和积累，从而导致种子更小、更轻。对种子成分的分析表明，热处理植株种子的含油量降低而蛋白质含量增加。此外，脂肪酸组成发生了变化，其中ω-3α-亚麻酸减少，ω-6亚油酸相应增加，且受影响最为显著。我们的结果还揭示了所研究的两个基因型的不同反应，表明亚麻荠种质中存在遗传变异，可用于探索提高耐热性。本研究为未来研究了解热应激的遗传和生理机制以及协助提高面对气候变化的亚麻荠生产可持续性提供了资源和指导。
