Fig. 7

The gravity signal plays a key role in setting the adventitious root GSA. (a) The gravitropic response of adventitious roots was measured by the angles between empty vector controls. Scale bars = 1 cm. 35S::MdFLP and 35S::MdFLP under microgravity. 35S::MdFLP adventitious roots display a smaller GSA than the adventitious roots of the empty vector control. However, 35S::MdFLP adventitious roots under microgravity have a larger GSA than the adventitious roots of the empty vector control and 35S::MdFLP. (b) Transcript levels of endogenous gravity-responsive genes in empty vector controls, 35S::MdFLP and 35S::MdFLP under microgravity. Error bars indicate ± SD (n = 3, from three technical replicates). Values in (b) were derived from experiments that were performed at least three times with similar results, and representative data from one replicate are shown. (c) Distributions of adventitious root GSAs. 35S::MdFLP show stronger gravitropic responses than the empty vector control, resulting in a smaller GSA. However, the 35S::MdFLP adventitious roots under microgravity have a larger GSA than the empty vector control and 35S::MdFLP adventitious roots. Samples with different letters are significantly different: P < 0.05 (Fisher’s LSD mean separation test). (d) The content of IAA in empty vector controls, 35S::MdFLP and 35S::MdFLP under microgravity. The 35S::MdFLP adventitious roots under microgravity showed higher IAA content than the adventitious roots of the empty vector control and 35S::MdFLP. Samples with different letters are significantly different: P < 0.05 (Fisher’s LSD mean separation test)