BackgroundTrehalose, a non-reducing disaccharide, which involves in the acquisition of various stress tolerance, while hydrogen sulfide (H2S) is considered as a cell signal molecule, but H2S-induced heat tolerance and involvement of trehalose in plants is still unclear.ResultsIn present study, pretreatment with hydrogen sulfide donor sodium hydrosulfide (NaHS) markedly increased the accumulation of endogenous H2S in maize seedlings under normal culture conditions, which in turn improved survival percentage of maize seedlings and mitigated increase in electrolyte leakage and malonaldehyde (MDA) accumulation under heat stress. In addition, treatment with NaHS activated increase in the activity of trehalose-6-phosphate phosphatase (TPP) under normal culture conditions, followed by induced the accumulation of endogenous trehalose, but this accumulation was eliminated by addition of sodium citrate, an inhibitor of TPP. During the process of heat stress, maize seedlings treated with NaHS maintained higher TPP activity and trehalose content than those of control. On the other hand, exogenous application of trehalose also increased the content of endogenous trehalose in maize seedlings under normal culture conditions, alleviated increase in electrolyte leakage and MDA accumulation under heat stress, which in turn improved survival percentage of maize seedlings, and the heat tolerance induced by trehalose was enhanced by exogenous supplement of NaHS, but exogenous trehalose treatment had not significant effect on the accumulation of endogenous hydrogen sulfide in maize seedlings.ConclusionThese data suggest that sodium hydrosulfide pretreatment could improve heat tolerance of maize seedlings and this improvement may be involved in trehalose accumulation by activating TPP activity.Electronic supplementary materialThe online version of this article (doi:10.1186/1999-3110-55-20) contains supplementary material, which is available to authorized users.

Hydrogen peroxide (H 2 O 2 ) and nitric oxide (NO) function as signal molecules in plant cells. Recently, hydrogen sulfide (H 2 S) has been found to have similar functions, but their interactions in the acqui sition of thermotolerance in plants remain elusive. In current work, pretreatment with H 2 O 2 rapidly induced endogenous H 2 O 2 accumulation, which in turn improved survival percentage of maize seedlings (Zea mays L.) under heat stress, but these effects were eliminated by H 2 O 2 scavenger dimethylthiourea indicating that H 2 O 2 induced thermotolerance was involved in the accumulation of endogenous H 2 O 2 . H 2 O 2 pretreatment also increased endogenous NO content, but this increase was abolished by NO scavenger cPTIO. Exogenously applied H 2 O 2 also stimulated increase in the activity of L cystine desulfhydrase, a key enzyme in H 2 S biosyn thesis, followed by inducing endogenous H 2 S accumulation, while this accumulation was diminished by cPTIO. In addition, H 2 O 2 induced thermotolerance was enhanced by NO donor sodium nitroprusside and H 2 S donors NaHS as well as GYY4137, respectively, and weakened by cPTIO, DL propargylglycine (inhibitor of H 2 S biosynthesis) and hypotaurine (H 2 S scavenger). All of the above mentioned results showed that H 2 O 2 treatment could improve thermotolerance in maize seedlings, and the acquisition of thermotolerance induced by H 2 O 2 may be involved in downstream signal crosstalk between NO and H 2 S.