plays an important role in resistance to aluminium toxicity. In addition to resistance to chemicals, the apoplast provides the rich environment for microorganisms endophytes which arises[??] the abiotic resistance of plants.[clarification needed] Exclusion of aluminium ions in[clarification needed: "EXclusion IN"??] the apoplast prevent toxic levels which inhibit shoot growth, reducing[?] crop yields. History The term apoplast was coined in 1930 by Münch in order to separate the "living" symplast from the "dead" apoplast. Apoplastic transport The apoplastic pathway is one of the two main pathways for water transport in plants, the other being symplastic pathway. In the root via the apoplast water and minerals flow in an upward direction to the xylem. The concentration of solutes transported through the apoplast in aboveground organs is established through a combination of import from the xylem, absorption by cells, and export by the phloem. Transport velocity is higher (transport is faster) in the apoplast than in the symplast. This method of transport also accounts for a higher proportion of water transport in plant tissues than does symplastic transport. The apoplastic pathway is also involved in passive exclusion.[clarification needed] Some of the ions that enter through the roots do not make it to the xylem. The ions are excluded by the cell walls (plasma membranes)[clarification needed: why would that hinder APOplastic flow?] of the endodermal cells. Apoplastic colonization It is well known that the apoplast in plants’ tissues contains rich mineral nutrients, and it becomes the main factor for microorganisms to thrive at the apoplast. Even though there are apoplastic immunity systems, but there are pathogens that have effectors that can modulate the host immunity or suppress the immunity responses as known as effector-triggered susceptibility. Another factor that pathogens colonize the apoplastic space so frequent is because when they enter the plants from leaves, the first place they come across is the apoplastic space. Therefore, the apoplast is a popular biotic interface and also a reservoir for microbes. One of the common apoplastic disease appear in plants without restricted habitat or climate is black rot, caused by the gram-negative bacteria Xanthomonas campestris. Entophytic bacteria can cause severe problems in agriculture in a way of inhibiting plant growth by alkalizing the apoplast with their volatiles. In especially, the rhizobacteria has been found that its major component of the volatiles are phytotoxic, it is identified as 2-phenylethanol. 2-phenylethanol can influence the regulation of WRKY18 which is