AUTHOR=Li Xiaolin , Fan Shuhong , Hu Wei , Liu Guoyin , Wei Yunxie , He Chaozu , Shi Haitao 

TITLE=Two Cassava Basic Leucine Zipper (bZIP) Transcription Factors (MebZIP3 and MebZIP5) Confer Disease Resistance against Cassava Bacterial Blight

JOURNAL=Frontiers in Plant Science

VOLUME=8

YEAR=2017

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2017.02110

DOI=10.3389/fpls.2017.02110

ISSN=1664-462X

ABSTRACT=<p>Basic domain-leucine zipper (bZIP) transcription factor, one type of conserved gene family, plays an important role in plant development and stress responses. Although 77 <italic>MebZIPs</italic> have been genome-wide identified in cassava, their <italic>in vivo</italic> roles remain unknown. In this study, we analyzed the expression pattern and the function of two <italic>MebZIPs</italic> (<italic>MebZIP3</italic> and <italic>MebZIP5</italic>) in response to pathogen infection. Gene expression analysis indicated that <italic>MebZIP3</italic> and <italic>MebZIP5</italic> were commonly regulated by flg22, <italic>Xanthomonas axonopodis</italic> pv. <italic>manihotis</italic> (<italic>Xam</italic>), salicylic acid (SA), and hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>). Subcellular localization analysis showed that MebZIP3 and MebZIP5 are specifically located in cell nucleus. Through overexpression in tobacco, we found that <italic>MebZIP3</italic> and <italic>MebZIP5</italic> conferred improved disease resistance against cassava bacterial blight, with more callose depositions. On the contrary, <italic>MebZIP3-</italic> and <italic>MebZIP5</italic>-silenced plants by virus-induced gene silencing (VIGS) showed disease sensitive phenotype, lower transcript levels of defense-related genes and less callose depositions. Taken together, this study highlights the positive role of <italic>MebZIP3</italic> and <italic>MebZIP5</italic> in disease resistance against cassava bacterial blight for further utilization in genetic improvement of cassava disease resistance.</p>