Department of Agriculture and Oenology, Eastern Region Research and Development Center, Ariel 40700, Israel.
The Department of Molecular Biology, Ariel University, Ariel 40700, Israel.
Tree Physiol. 2021 Jul 5;41(7):1199-1211. doi: 10.1093/treephys/tpaa181.
Perennial plants perpetually adapt to environmental changes in complex and yet insufficiently understood manner. We aimed to separate the intra-seasonal temperature effects on structure and function from perennial and annual water stress effects. This study focused on grapevine (Vitis vinifera L. 'Cabernet Sauvignon') petioles, which being a continuously produced organ, represent the current status of the plant. Field-grown mature plants subjected to multi-annual irrigation treatments (severe water stress, mild water stress and non-stressed) throughout the growing season were compared with greenhouse-grown plants under three temperature regimes (22, 28 and 34 °C). Physiological and functional anatomy parameters were measured. A generalized additive model (GAM) based on meteorological and lysimeter-based field data was applied to determine the relative influence of various meteorological parameters on evapotranspiration (ETc) during the growing season in the field experiment. At the beginning of the growing season, in May, petioles in the severe stress treatment showed a stress-related structure (decreased length, safer hydraulic structure and increased lignification), though having high values of stem water potential (SWP). As the season progressed and temperatures increased, all water availability treatments petioles showed similar changes, and at the end of season, in August, were structurally very similar. Those changes were independent of SWP and were comparable to high temperature-induced changes in the greenhouse. In contrast, stems hydraulic structure was strongly influenced by water availability. Regression analyses indicated a relationship between petioles xylem structure and stomatal conductance (gs), whereas gs (but not SWP) was temperature-dependent. The GAM showed that ETc was mainly dependent on temperature. Our results indicate a perennial water-stress memory response, influencing the petiole structure at the beginning of the following season. Intra-seasonally, the petiole's structure becomes independent of water status, whereas temperature drives the structural changes. Thus, ongoing climate change might disrupt plant performance by purely temperature-induced effects.
多年生植物以复杂且尚未充分理解的方式不断适应环境变化。我们旨在将季节内温度对结构和功能的影响与多年生和一年生水分胁迫的影响分开。本研究集中在葡萄（Vitis vinifera L. '赤霞珠'）叶柄上，作为一个不断产生的器官，它代表了植物的当前状态。在整个生长季节中，对田间生长的成熟植物进行了多年度的灌溉处理（严重水分胁迫、轻度水分胁迫和非胁迫），并与温室生长的植物在三种温度条件下进行了比较（22、28 和 34°C）。测量了生理和功能解剖参数。应用基于气象和蒸渗仪田间数据的广义加性模型（GAM）来确定在田间实验中生长季节期间各种气象参数对蒸散（ETc）的相对影响。在生长季节开始的五月份，严重胁迫处理的叶柄表现出与胁迫相关的结构（长度缩短、更安全的水力结构和木质化增加），尽管木质部水势（SWP）值较高。随着季节的进展和温度的升高，所有水分供应处理的叶柄都表现出相似的变化，在八月份季节结束时，它们在结构上非常相似。这些变化与 SWP 无关，与温室中高温诱导的变化相当。相比之下，茎的水力结构受到水分供应的强烈影响。回归分析表明叶柄木质部结构与气孔导度（gs）之间存在关系，而 gs（但不是 SWP）取决于温度。GAM 表明 ETc 主要取决于温度。我们的结果表明，存在多年生水分胁迫记忆反应，在下一个季节开始时影响叶柄结构。在季节内，叶柄的结构变得独立于水分状况，而温度则驱动结构变化。因此，持续的气候变化可能会纯粹通过温度诱导的影响扰乱植物的表现。
