Tissue specific response of Agrobacterium tumefaciens attachment to Sorghum bicolor (L) Moench

Abstract

Agrobacterium mediated genetic transformation of plants have advantages over other methods, especially for making single copy transgenic plants with reduced chances of gene silencing and instability. However, monocotyledonous plant species could not utilize the full potential of this system because of possible limitations in Agrobacterium interaction with monocot plant cells. Agrobacterium attachment as a factor in genetic transformation was studied in the leaf, shoot apex, and leaf derived callus of sorghum (Sorghum bicolor (L) Moench). Pre-induction of Agrobacterium with acetosyringone was found necessary for Agrobacterium attachment to sorghum tissues. All the explants responded positively, with preferential Agrobacterium attachment and colonization around the tissues having actively dividing cells. Callus proved to be the best explant for Agrobacterium attachment as observed in scanning electron microscopy and transient GUS expression. Loss of Agrobacterium attachment was observed with an increase in the degree of tissue differentiation.

Efficient Agrobacterium-Mediated Transformation of Hybrid Poplar Populus davidiana Dode × Populus bollena Lauche

“…A possible reason for the observed differential response of Agrobacterium invasion in different tissues was because of changes in the cell wall composition at different physiologic and developmental stages. As the plant cells mature, their cell wall composition changes so that Agrobacterium -binding sites were gradually lost [43]. …”

Sorghum Transformation: Achievements, Challenges, and Perspectives

“…However, similar to some other cereals, sorghum has been recalcitrant to Agrobacterium-mediated transformation. The interaction between bacterial cells and sorghum tissue could be improved by preinduction of Agrobacterium with acetosyringone, using tissues that have actively dividing cells, and heat-cold pretreatment of explants (Verma et al 2008;Gurel et al 2009). Other ways to increase transformation include the use of greater concentrations of Agrobacterium or longer cocultivation time (Zhao et al 2000).…”

Leaf Age Promotes Agrobacterium-mediated Transformation of Hybrid Poplar Populus Davidiana Dode x P. bollena Lauche

“…As the plant cell gets mature, its cell wall composition changes in such a way that Agrobacterium binding sites are lost gradually. Mature cells of intact leaf epidermis having limited number Agrobacterium attachment sites have evenly distributed Agrobacterium while undifferentiated explants and split shoot apex having young cells with plenty of Agrobacterium attachment sites favored development of Agrobacterium aggregates [9].…”