Proline-stimulated signaling primarily targets the chlorophyll degradation pathway and photosynthesis associated processes to cope with short-term water deficit in maize

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Küçük Resim

Tarih

2020

Dergi Başlığı

Dergi ISSN

Cilt Başlığı

Yayıncı

Springer

Erişim Hakkı

info:eu-repo/semantics/closedAccess

Özet

Increased photosynthetic efficiencies in genotypes with greater proline level and in crops treated with proline under water deficit have been reported in recent years, but the biochemical and molecular mechanisms of this process are still not known. We examined photosystem II (PSII) activity, photosynthetic enzymes, ribulose 1,5-bisphosphate carboxylase/oxygenase (rubisco), phosphoenolpyruvate carboxylase (PEPc), rubisco activase (RCA), and chlorophyll metabolic enzymes, magne-sium chelatase (Mg-CHLI), and chlorophyllase (Chlase), which would be the primary targets of exogenous proline to provide photosynthetic protection to plants under PEG-induced short-term water deficit. Two maize genotypes W23/M14 with greater proline content and Şafak with low proline content were hydroponically grown for 21–23 days, and then the seedlings were subjected to water deficit (? 0.75 MPa) induced by PEG6000 for 0, 4, and 8 h. Before the seedlings were exposed to the water deficit, proline (1 mM) was applied to the rooting medium of the Şafak genotype for 2 days. The time course effects of the applications showed that exogenous proline significantly enhanced PSII efficiency, PEPc activity, rubisco activity, and the relative expression levels of PEPc, rubisco large subunit, rubisco small subunit, and RCA genes at 0, 4, and 8 h. The W23/M14 genotype had higher rubisco quantity than the Şafak genotype at all time periods. Proline pre-treatment under the stress-free and PEG conditions reduced the activity of Chlase and the gene expressions of Chlase, while it enhanced Mg-CHLIgene expression at 0, 4, and 8 h. Taken together, the results indicated that the primary target of proline-stimulated signaling in maize seedlings exposed to short-term severe water deficit may be to induce PSII efficiency, activities of carbon dioxide fixation enzymes and chlorophyll metabolism and mitigate chlorophyll degradation.

Açıklama

Anahtar Kelimeler

Water deficit, Proline treatment, Photosynthesis, Rubisco, Magnesium chelatase, Chlorophyllase, Gene expression

Kaynak

Photosynthesis Research

WoS Q Değeri

Q1

Scopus Q Değeri

Q1

Cilt

144

Sayı

1

Künye

Altuntaş, C., Demiralay, M., Sezgin Muslu, A., & Terzi, R. (2020). Proline-stimulated signaling primarily targets the chlorophyll degradation pathway and photosynthesis associated processes to cope with short-term water deficit in maize. Photosynthesis Research: Official Journal of the International Society of Photosynthesis Research, 144(1), pp. 35-48, https://doi.org/10.1007/s11120-020-00727-w