AUTHOR=Zhang Peng-Jun , He Yu-Chen , Zhao Chan , Ye Zi-Hong , Yu Xiao-Ping 

TITLE=Jasmonic Acid-Dependent Defenses Play a Key Role in Defending Tomato Against Bemisia tabaci Nymphs, but Not Adults

JOURNAL=Frontiers in Plant Science

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2018.01065

DOI=10.3389/fpls.2018.01065

ISSN=1664-462X

ABSTRACT=<p>The silverleaf whitefly <italic>Bemisia tabaci</italic> is an important and invasive crop pest in many countries. Previous laboratory studies with <italic>Arabidopsis</italic> demonstrated that <italic>B. tabaci</italic> can suppress jasmonic acid (JA) defenses and thereby enhance <italic>B. tabaci</italic> performance. Whether <italic>B. tabaci</italic> can suppress JA-regulated host plant defenses in field is unknown. In the present study, we found that, relative to wild-type (WT) tomato plants, transgenic tomato mutants that activated JA defenses (<italic>35s::prosys</italic>) or impaired JA defenses (<italic>spr-2</italic> and <italic>def-1</italic>) did not affect the survival or reproduction of <italic>B. tabaci</italic> adults in growth chamber experiments. In contrast, tomato mutants that activated JA defenses slowed <italic>B. tabaci</italic> nymphal development, while mutants that impaired JA defenses accelerated nymphal development. These effects of JA defenses on nymphal development were also documented under semi-field conditions. Changes in the expression of defense genes and in the production of phytohormones indicated that <italic>B. tabaci</italic> adults can suppress JA-dependent defenses after infestation for &gt;72 h. The suppression of JA was correlated with the induction of salicylic acid (SA) in <italic>B. tabaci</italic>-infested leaves under laboratory and under semi-field conditions. If SA signaling was blocked, JA accumulation increased in infested leaves and <italic>B. tabaci</italic> nymphal development was delayed. These results indicate that, although JA signaling helps in mediating tomato responses against <italic>B. tabaci</italic> nymphs, <italic>B. tabaci</italic> can inhibit JA biosynthesis and its action in an SA-dependent manner.</p>