Plants continuously modify their structure as a result of tissue maturation and environmental changes. In particular, temperature is a dominant factor in plant growth and development. We focused on long-term high temperature exposure, as well as short-term high temperature stress responses in grapevine (Vitis vinifera ‘Cabernet Sauvignon’).
Each branch internode, with the organs growing on it, can be seen as a single morphological phytomer subunit made of structurally and functionally interrelated components. Our findings suggest that allometric relationships along grapevine shoots are not constant; they exhibit a bimodal pattern, influenced by seasonal temperatures. Additionally, growing under high temperature (34°C) increases investment in phloem development in parallel with increased main long-distance transported sugar (sucrose) accumulation. Moreover, our results indicate a perennial water-stress memory response, determining the petiole structure at the beginning of the subsequent growing season, while intra-seasonally, increasing seasonal temperature drives the structural changes. Xylem vessels diameter (>30 µm) was influenced by temperature and not water status. Exposure to short term heat stress induced the expression of small heat shock proteins, cell wall remodelling and changes in petiole functional anatomy, and established a priming state toward high temperature.
Altogether, our studies show that temperature has a pivotal importance in grapevine, inducing an array of plastic responses. Plant memory seems to play an important part in adaptations to stress, which ultimately will lead to development of priming-based strategies for the purpose of improved crop performance.
