Silencing ribulose-1,5-bisphosphate carboxylase/oxygenase expression does not disrupt nitrogen allocation to defense after simulated herbivory in Nicotiana attenuata
Silencing ribulose-1,5-bisphosphate carboxylase/oxygenase expression does not disrupt nitrogen allocation to defense after simulated herbivory in Nicotiana attenuata
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DOI：
10.4161/psb.27570
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发表时间：
2013-12
影响因子：
2.9
通讯作者：
M. A. Stanton;Lynn Ullmann-Zeunert;N. Wielsch;S. Bartram;A. Svatoš;I. Baldwin;K. Groten
中科院分区：
文献类型：
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作者：
M. A. Stanton;Lynn Ullmann-Zeunert;N. Wielsch;S. Bartram;A. Svatoš;I. Baldwin;K. Groten
核酮糖-1,5-二磷酸羧化酶/加氧酶（RuBisCO）是地球上最丰富的蛋白质，除了在光合作用中起核心作用外，它还被认为是一种氮(N)储存蛋白和植物防御生物合成的潜在N来源。在最近的一项野生烟草研究中，我们发现模拟草食引起的可溶性蛋白和RuBisCO绝对氮的减少远远大于尼古丁和酚胺生物合成所需的氮；15N通量研究表明，防御性酚醛酰胺合成的N来源于最近同化的N，而不是RuBisCO的周转。本研究表明，与野生型植物相比，RuBisCO （asRUB）表达沉默的转基因N. attenuata株系将相似甚至更多的N投入到苯酰胺的生物合成中，这与我们之前的结论一致，即最近吸收的N在诱导后被引导到苯酰胺的合成中。我们认为，模拟草食后叶片蛋白质的减少是一种耐受机制，而不是防御生物合成所需n的结果。
Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) is the most abundant protein on the planet and in addition to its central role in photosynthesis it is thought to function as a nitrogen (N)-storage protein and a potential source of N for defense biosynthesis in plants. In a recent study in the wild tobacco Nicotiana attenuata, we showed that the decrease in absolute N invested in soluble proteins and RuBisCO elicited by simulated herbivory was much larger than the N-requirements of nicotine and phenolamide biosynthesis; 15N flux studies revealed that N for defensive phenolamide synthesis originates from recently assimilated N rather than from RuBisCO turnover. Here we show that a transgenic line of N. attenuata silenced in the expression of RuBisCO (asRUB) invests similar or even larger amounts of N into phenolamide biosynthesis compared with wild type plants, consistent with our previous conclusion that recently assimilated N is channeled into phenolamide synthesis after elicitation. We suggest that the decrease in leaf proteins after simulated herbivory is a tolerance mechanism, rather than a consequence of N-demand for defense biosynthesis.