Gómez-Ocampo Gabriel, Cascales Jimena, Medina-Fraga Ana L, Ploschuk Edmundo L, Mantese Anita I, Crocco Carlos D, Matsusaka Daniel, Sánchez Diego H, Botto Javier F
IFEVA (CONICET-UBA), Facultad de Agronomía, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina.
Cátedra de Cultivos Industriales, Facultad de Agronomía, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina.
Physiol Plant. 2023 Jul-Aug;175(4):e13991. doi: 10.1111/ppl.13991.
Plants detect competitors in shaded environments by perceiving a reduction in photosynthetically active radiation (PAR) and the reduction between the red and far-red light (R:FR) ratio and blue photons. These light signals are detected by phytochromes and cryptochromes, which trigger shade avoidance responses such as shoot and petiole elongation and lead to increased susceptibility to pathogen attack. We studied morphological, anatomical, and photosynthesis differences in potato plants (Solanum tuberosum var. Spunta) exposed to sunlight or simulated shade in a greenhouse. We found that simulated shade strongly induced stem and internode elongation with a higher production of free auxin in stems and a lower production of tubers. The mesophyll thickness of the upper leaves of plants grown in simulated shade was lower, but the epidermis was wider compared with the leaves of plants cultivated in sunlight. In addition, the photosynthesis rate was lower in the upper leaves exposed to nonsaturated irradiances and higher in the basal leaves at saturated irradiances compared with control plants. RNA-seq analysis showed that 146 and 155 genes were up- and downregulated by shade, respectively. By quantitative reverse transcription polymerase chain reaction, we confirmed that FLOWERING LOCUS T (FT), WRKY-like, and PAR1b were induced, while FLAVONOL 4-SULFOTRANSFERASE was repressed under shade. In shaded plants, leaves and tubers were more susceptible to the necrotrophic fungus Botrytis cinerea attack. Overall, our work demonstrates configurational changes between growth and defense decisions in potato plants cultivated in simulated shade.
植物通过感知光合有效辐射（PAR）的减少以及红光与远红光（R:FR）比率和蓝光光子的减少来检测阴凉环境中的竞争者。这些光信号由光敏色素和隐花色素检测到，它们会触发避荫反应，如茎和叶柄伸长，并导致对病原体攻击的易感性增加。我们研究了温室中暴露于阳光或模拟阴凉下的马铃薯植株（Solanum tuberosum var. Spunta）的形态、解剖结构和光合作用差异。我们发现，模拟阴凉强烈诱导茎和节间伸长，茎中游离生长素产量更高，块茎产量更低。与在阳光下种植的植株叶片相比，模拟阴凉下生长的植株上部叶片的叶肉厚度较低，但表皮更宽。此外，与对照植株相比，暴露于非饱和辐照度下的上部叶片的光合速率较低，而在饱和辐照度下基部叶片的光合速率较高。RNA测序分析表明，分别有146个和155个基因在阴凉条件下上调和下调。通过定量逆转录聚合酶链反应，我们证实了在阴凉条件下，开花位点T（FT）、WRKY样基因和PAR1b被诱导，而黄酮醇4-磺基转移酶受到抑制。在阴凉条件下生长的植株中，叶片和块茎更容易受到坏死性真菌灰葡萄孢的攻击。总体而言，我们的工作证明了模拟阴凉条件下种植的马铃薯植株在生长和防御决策之间的结构变化。
