The locoweed endophyte Alternaria oxytropis affects root development in Arabidopsis in vitro through auxin signaling and polar transport.
The locoweed endophyte Alternaria oxytropis affects root development in Arabidopsis in vitro through auxin signaling and polar transport.
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疯草内生菌链格孢 (Alternaria oxytropis) 通过生长素信号传导和极性运输影响体外拟南芥根部发育。
DOI：
10.1093/jxb/erac430
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发表时间：
2023
影响因子：
6.9
通讯作者：
Guan H
中科院分区：
文献类型：
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作者：
Guan H
疯草是豆科杂草，因其对家畜的毒性而闻名，由内生真菌交链孢杆菌引起。与许多产生毒素的内生菌及其植物寄主中报道的防御性互惠不同，A.sect.Undifilum能赋予寄主植物什么好处尚不清楚。在这里，我们进行了生理和遗传分析表明，在其疯草寄主棘豆和拟南芥中，氧化应激影响其生长，特别是根的发育。英国足协的存在。促氧化作用显著降低了初生根的长度，增加了侧根和根毛的数量，增加了植株叶面积和鲜重。该真菌还增加了植物内源生长素的浓度，以及生长素生物合成、信号传递和运输的关键基因的表达。缺乏生长素信号和极性运输的突变体取消了这些对根发育的影响。氧化链格孢菌下调了PIN1的表达，而上调了PIN2、PIN7和AUX1的表达，这可能反映了生长素空间积累的变化，从而导致了根构型的变化。植物生长对ToA不敏感。当使用萘基邻苯二甲酸时，会产生促氧化作用。我们的发现表明了FA的功能。促生长素通过调节生长素来促进拟南芥的生长发育，而生长素可能通过一个独立于其毒素产生的过程而使其疯草宿主受益。
Locoweeds are leguminous forbs known for their toxicity to livestock caused by the endophytic fungiAlternariasect.Undifilum. Unlike the defensive mutualisms reported in many toxin-producing endophytes and their plant hosts, the benefits thatA.sect.Undifilumcan confer to it host plants remains unclear. Here, we conducted physiological and genetic analyses to show thatA.(sect.Undifilum)oxytropisinfluences growth, especially root development, in its locoweed hostOxytropis ochrocephalaand Arabidopsis. The presence ofA. oxytropissignificantly decreased primary root length while increasing the numbers of lateral roots and root hairs, and increasing plant leaf area and fresh weight. The fungus also increased the concentrations of plant endogenous auxin, and the expression of key genes for auxin biosynthesis, signaling, and transport. These effects on root development were abolished in mutants deficient in auxin signaling and polar transport.Alternaria oxytropisdown-regulated expression ofPIN1but increased expression ofPIN2,PIN7, andAUX1, which might reflect alterations in the spatial accumulation of auxin responsible for the changes in root architecture. Plant growth was insensitive toA. oxytropiswhen naphthylphthalamic acid was applied. Our findings indicate a function ofA. oxytropisin promoting the growth and development of Arabidopsis via the regulation of auxin, which in turn suggests a possible role in benefiting its locoweed hosts via a process independent of its toxin production.