TMTM affects root lengths
To examine whether TMTM affects the root growth under sulfur deficiency, 5-days old seedlings of wild-type (Col-0 ) and slim1 , a mutant which fails to respond to sulfur deficiency (Maruyama-Nakashitaet al. , 2006), were transferred to LS medium and grown vertically for additional 7 days. Figure 4 shows the increase in the root lengths after 7 days. Compared to LS condition without TMTM, the root lengths of both wild-type (WT) and slim1 seedlings were significantly higher when they were exposed to 100 µg TMTM (≈ 9% and 7% increase for WT andslim1 , respectively; Figure 4A and 4B) and reached the level of seedlings which were grown on HS medium without the volatile. In accordance with the fresh and dry weight data, addition of 1000 µg TMTM reduced the root growth rate in WT for about 10% (Figure 4A). Interestingly, the reduction in root growth was not affected inslim1 (≈ 1% reduction compared to LS without TMTM; Figure 4B). The differences might be due to an effect of TMTM on the sulfur homeostasis.