Brütting Christoph, Schäfer Martin, Vanková Radomíra, Gase Klaus, Baldwin Ian T, Meldau Stefan
Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Hans Knöll Str. 8, Jena, 07745, Germany.
Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany AS CR, Rozvojová 263, Prague 6 - Lysolaje, 165 02, Czech Republic.
Plant J. 2017 Jan;89(1):15-30. doi: 10.1111/tpj.13316.
Plant defense metabolites are well known to be regulated developmentally. The optimal defense (OD) theory posits that a tssue's fitness values and probability of attack should determine defense metabolite allocations. Young leaves are expected to provide a larger fitness value to the plant, and therefore their defense allocations should be higher when compared with older leaves. The mechanisms that coordinate development with defense remain unknown and frequently confound tests of the OD theory predictions. Here we demonstrate that cytokinins (CKs) modulate ontogeny-dependent defenses in Nicotiana attenuata. We found that leaf CK levels highly correlate with inducible defense expressions with high levels in young and low levels in older leaves. We genetically manipulated the developmental patterns of two different CK classes by using senescence- and chemically inducible expression of CK biosynthesis genes. Genetically modifying the levels of different CKs in leaves was sufficient to alter ontogenic patterns of defense metabolites. We conclude that the developmental regulation of growth hormones that include CKs plays central roles in connecting development with defense and therefore in establishing optimal patterns of defense allocation in plants.
植物防御代谢产物在发育过程中受到调控，这是众所周知的。最佳防御（OD）理论认为，组织的适合度值和受攻击的概率应决定防御代谢产物的分配。幼叶预期会为植物提供更大的适合度值，因此与老叶相比，其防御分配应该更高。协调发育与防御的机制仍然未知，并且经常混淆对OD理论预测的测试。在这里，我们证明细胞分裂素（CKs）调节了黄花烟草中依赖个体发育的防御。我们发现叶片CK水平与诱导型防御表达高度相关，幼叶中水平高，老叶中水平低。我们通过使用衰老诱导和化学诱导的CK生物合成基因表达，对两种不同CK类别的发育模式进行了基因操作。在叶片中对不同CK水平进行基因改造足以改变防御代谢产物的个体发育模式。我们得出结论，包括CKs在内的生长激素的发育调控在将发育与防御联系起来方面起着核心作用，因此在建立植物防御分配的最佳模式方面也起着核心作用。
