Although no partner differentiation takes place, it makes sense that during evolution, modifications of root phenotypic properties facilitating bacterial nitrogen fixation and thereby the supply of available nitrogen to the plant could have been selected.
Extensive modifications of root cell walls, as substantiated by cell wall outgrowth and induction of genes encoding cell wall synthesizing, loosening and degrading enzymes, may facilitate the uptake of microbes into root cells.
Altogether, our results indicate that uptake of microbes by roots occurs through major structural modifications of root cells controlled by the plant, including outgrowth of a cell-wall like structure capturing microbes, and degradation and/or loosening of cell walls with plant-derived enzymes.
First, the direct Pi acquisition pathway acts through modifications of root architecture, root length and lateral root numbers [ 42- 44].
Previous studies suggested that ga5 might be more drought-tolerant due to modifications of root system architecture (Vartanian et al., 1994).
Modifications of root growth can have an impact on the growth performance of plants under stress conditions and genetic variation in the hormonal pathways may affect root traits (Ghanem et al., 2011).
This feeding method differs from that of other nematodes related to Xiphinema spp. including Longidorus spp. and more distantly related Tylenchids, many of which involve modifications of root cortex cells and a notable host response.
Exposure to CuONPs resulted in suppression of shoot-growth, reduction in total chlorophyll and carotenoids contents as well modification of root system architecture such as shortening of primary and lateral roots.
To cope with suboptimal Pi conditions, plants have developed a series of adaptive responses, such as induction of Pi transporters and modification of root system architecture (Raghothama, 1999; Lin et al., 2009; Wu et al., 2013).
Repression of genes participating in cell wall and protein synthesis might be relevant for the modification of root architecture, a characteristic response in P-starved roots [ 29- 32].
