Rizzuto Gabriele, Wang Dapeng, Chen Jinhui, Hung Tin Hang, Fitzky Anne Charlott, Flashman Emily, MacKay John J
Department of Biology, University of Oxford, South Parks Road, Oxford OX1 3RB, UK.
Department of Earth and Marine Sciences (DiSTeM), University of Palermo, viale delle Scienze Ed. 16, Palermo, 90128, Italy.
Plant Stress. 2024 Dec;14:None. doi: 10.1016/j.stress.2024.100574.
Conifer trees have diverse strategies to cope with drought. They accumulate the plant hormone abscisic acid (ABA) following a range of profiles from constantly rising to peaking and falling (R- and P-type) with direct effect on foliar transpiration. The molecular basis of this adaptive diversification among species is largely unknown. Here, we analysed the sequences of candidate ABA biosynthesis and catabolism genes and monitored their expression in response to intensifying drought. We studied young trees from Cupressaceae, Pinaceae, and Taxaceae under controlled drought conditions and compared changes in water status, ABA profiles and gene-specific transcript levels. Our data indicate that R-type and P-type ABA profiles may be controlled by divergent expression of genes involved in the biosynthetic and catabolic pathways of ABA, respectively, and emphasize a key role of nine--epoxycarotenoid dioxygenases () genes. Our results open the doors to understanding the molecular basis of contrasted drought response strategies across conifer taxa, which we expect will help foresters grow more drought-resilient trees.
针叶树有多种应对干旱的策略。它们会积累植物激素脱落酸（ABA），其积累模式多样，从持续上升到达到峰值后下降（R型和P型），这对叶片蒸腾作用有直接影响。物种间这种适应性多样化的分子基础在很大程度上尚不清楚。在此，我们分析了ABA生物合成和分解代谢相关候选基因的序列，并监测它们在干旱加剧时的表达情况。我们在可控干旱条件下研究了柏科、松科和红豆杉科的幼树，比较了水分状况、ABA积累模式和基因特异性转录水平的变化。我们的数据表明，R型和P型ABA积累模式可能分别由ABA生物合成和分解代谢途径中相关基因的不同表达所控制，并强调了9-顺式环氧类胡萝卜素双加氧酶（NCED）基因的关键作用。我们的研究结果为理解针叶树类群中不同干旱响应策略的分子基础打开了大门，我们期望这将有助于林业工作者培育出更耐旱的树木。
