Developmental changes in the potential for h(2)s emission in cucurbit plants

Area of Science:

• Plant Physiology
• Biochemistry
• Environmental Science

Background:

• Hydrogen sulfide (H2S) is a signaling molecule in plants.
• H2S emission in plants is influenced by various factors, including substrate availability and plant development.
• Understanding H2S metabolism is crucial for plant health and stress response.

Purpose of the Study:

• To investigate the developmental regulation of H2S emission potential in cucurbit plants.
• To determine the differential response of H2S emission to sulfate and l-cysteine based on plant and leaf age.
• To correlate H2S emission with cysteine desulfhydrase activity during plant development.

Main Methods:

• Leaf disc assays were used to measure H2S emission in response to sulfate and l-cysteine.
• Experiments were conducted on cucurbit plants (Cucurbita pepo and Cucumis sativus) of different ages (1-2.5 weeks and 3-4 weeks).
• Cysteine desulfhydrase activity (overt and latent) was extracted and measured from leaf tissues.

Main Results:

• Younger cucurbit plants (1-2.5 weeks) exhibited low H2S emission in response to sulfate but higher emission in response to l-cysteine.
• Older cucurbit plants (3-4 weeks) showed significantly increased H2S emission in response to sulfate, but decreased emission in response to l-cysteine with leaf age.
• Cysteine desulfhydrase activity paralleled H2S emission patterns, with higher activity in younger plants and a decline with increasing leaf age.

Conclusions:

• The potential for H2S emission in cucurbits is differentially regulated by plant age and substrate.
• Sulfate-induced H2S emission potential increases with plant development, while l-cysteine-induced potential is higher in younger plants and decreases with leaf age.
• Cysteine desulfhydrase activity is a key enzyme in H2S production and its developmental expression is linked to H2S emission patterns.