据国外媒体报道，荷兰科学家的最近一项研究显示，许多草本植物，如草莓、苜蓿、芦苇、羊角芹等会通过匍匐茎彼此连接成为一个庞大的植物网络，并维持很长一段时间。这种类似于计算机网络的连接可使植物分享一些信息，这是科学家首次发现植物间的网状交流现象，也促使我们重新审视周围的植物。
这项研究由荷兰内梅亨大学的司徒爱佛(Stuefer)与Nijmegen共同主持。他们培育了一些苜蓿及其它植物进行研究，苜蓿、草莓都属于有匍匐茎的植物，这种植物的特点是除通过种子进行有性繁殖外，还可通过匍匐茎进行无性繁殖，有趣的是，自然状态下匍匐茎长出新植株很久以后仍不腐烂，新植株借助于产生它的匍匐茎与母株相连。这样匍匐茎将众多的植株连在一起，形成匍匐茎网络。
上述现象我们其实知道很久了，但从没有人考虑过植物会利用匍匐茎形成的这个网络交流信息。现在，司徒爱佛与同事第一次发现，苜蓿可在害虫来临后通过匍匐茎网络发出内信号。如果一株苜蓿被毛毛虫侵袭，它会向与它相连的其它苜蓿发出内信号，接收到内信号的苜蓿会继续传递这种信号，从而使匍匐茎网络内的苜蓿都得到通知；同时，接收到内信号的苜蓿会改变植物体的化学成分，增加力学阻力，使自己变得不再惹虫子吃。通过这个网络，苜蓿等植物能够领先侵袭者一步做好防御准备，研究显示植物通过匍匐茎网络共享信息确实可以大大减少所受损失。然而，有利就有弊，正如互联网方便了我们共享信息但却同时引来了无数的病毒一样，司徒爱佛也发现，植物病毒也可利用匍匐茎网络迅速感染所有相连的植物。
Recent research from Vidi researcher Josef Stuefer at the Radboud University Nijmegen reveals that plants have their own chat systems that they can use to warn each other. Therefore plants are not boring and passive organisms that just stand there waiting to be cut off or eaten up. Many plants form internal communications networks and are able to exchange information efficiently.
Chat network
Many herbal plants such as strawberry, clover, reed and ground elder naturally form networks. Individual plants remain connected with each other for a certain period of time by means of runners. These connections enable the plants to share information with each other via internal channels. They are therefore very similar to computer networks. But what do plants want to chat to each other about?
Recently Stuefer and his colleagues were the first to demonstrate that clover plants warn each other via the network links if enemies are nearby. If one of the plants is attacked by caterpillars, the other members of the network are warned via an internal signal. Once warned, the intact plants strengthen their chemical and mechanical resistance so that they are less attractive for advancing caterpillars. Thanks to this early warning system, the plants can stay one step ahead of their attackers. Experimental research has revealed that this significantly limits the damage to the plants.
Viruses
However there are two sides to the coin. That is not just the case for the Internet but also for plants. It appears that plant viruses can use the infrastructure present to rapidly spread through the connected plants. The infection of one plant therefore leads to the infection of all plants within the network.
This research clearly reveals that the general image of plants is a poor reflection of reality. Who had now suspected that the majority of plants around us are constantly internetting?
This research is part of the Vidi project 'Plant Intranets. Costs, benefits, & risks of communication pathways in clonal plant networks' that was funded by NWO and the Radboud University Nijmegen.
Image: Clover plants can warn each other via a network of runners.
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Note for editors, not for publication
For further information please contact:
Dr Josef Stuefer (Radboud University Nijmegen) t.: +31 24 365 2912, j.stuefer@science.ru.nl www.eco.science.ru.nl/expploec/josef.htm
