Jené Laia, Munné-Bosch Sergi
Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, Spain.
Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, Spain; Institute of Nutrition and Food Safety (INSA), University of Barcelona, Barcelona, Spain.
Plant Sci. 2023 Nov;336:111856. doi: 10.1016/j.plantsci.2023.111856. Epub 2023 Sep 3.
Previous studies have shown that caffeine (1,3,7-trimethylxanthine) has some potential for its use as a biostimulant ingredient for boosting lentil production at suboptimal temperatures. However, some limitations to its use include its potential side effects as an emerging contaminant and the current lack of knowledge of its mechanism of action. Here, we aimed to study the mechanisms underlying improved lentil production upon caffeine application. Greenhouse-grown plants treated with caffeine (at 10 M, 10 M, and 10 M) were compared to an untreated, control treatment, and both reproductive and vegetative vigour were evaluated in parallel with endogenous foliar concentrations of phytohormones, including both stress and growth-related hormones. Results showed an enhanced lentil production at the highest caffeine concentration (10 M) which might be attributed, at least in part, to a greater vegetative vigour. The hormonal profiling revealed a dual effect. Firstly, there was a specific increase in jasmonoyl-isoleucine (JA-Ile) in the short term, which may provide a priming effect. Secondly, abscisic acid (ABA) content kept at low levels and the active cytokinin (CK) isopentenyl adenine (2-iP) increased and persisted at high levels throughout the reproductive stage. Cytokinin-mediated effects on growth, and more specifically the high CK/ABA ratios in leaves, appeared to mediate caffeine-related effects in boosting vegetative vigour. In conclusion, caffeine emerges as a compelling alkaloid for integration into biostimulant formulations due to its favorable effect in boosting lentil production through an improvement of vegetative vigour. These outcomes appear to be modulated by phytohormones, most notably jasmonates, priming plants for improved performance under suboptimal temperatures, and cytokinins, alongside ABA and its associated ratios, collectively enhancing plant growth and reproductive vigour in challenging conditions.
先前的研究表明，咖啡因（1,3,7 - 三甲基黄嘌呤）有潜力作为一种生物刺激剂成分，用于在次优温度下提高小扁豆产量。然而，其使用存在一些局限性，包括作为一种新兴污染物的潜在副作用以及目前对其作用机制缺乏了解。在此，我们旨在研究施用咖啡因后小扁豆产量提高的潜在机制。将温室种植的用咖啡因（10⁻⁶M、10⁻⁵M和10⁻⁴M）处理的植株与未处理的对照处理进行比较，并将生殖和营养活力与包括应激和生长相关激素在内的植物激素的内源叶浓度进行平行评估。结果表明，在最高咖啡因浓度（10⁻⁴M）下小扁豆产量有所提高，这至少部分可归因于更强的营养活力。激素分析揭示了双重效应。首先，短期内茉莉酰异亮氨酸（JA - Ile）有特定增加，这可能提供一种引发效应。其次，脱落酸（ABA）含量保持在低水平，而活性细胞分裂素（CK）异戊烯基腺嘌呤（2 - iP）增加并在整个生殖阶段持续保持在高水平。细胞分裂素介导的对生长的影响，更具体地说是叶片中高CK/ABA比值，似乎介导了咖啡因在促进营养活力方面的相关效应。总之，由于咖啡因通过改善营养活力对提高小扁豆产量具有有利作用，它成为一种有吸引力的生物碱，可纳入生物刺激剂配方中。这些结果似乎受到植物激素的调节，最显著的是茉莉酸酯，使植物在次优温度下表现更好，以及细胞分裂素，与ABA及其相关比值一起，在具有挑战性的条件下共同增强植物的生长和生殖活力。
