Priming-Induced Metabolic Changes in Sunflower (Helianthus annuus) Achenes Improve Germination and Seedling Growth

在向日葵瘦果以先期誘導技術所引起之代謝改變可以改善種子萌發及幼苗生長

Abdul Wahid ； Asma Noreen ； Shahzad M.A. Basra ； Sadia Gelani ； M. Farooq

《Botanical Studies》 49卷4期 (2008/10) Pp. 343-350

摘要

種子之先期誘導可增進生長勢，唯其效果因所用藥劑而異。本研究分別以低於極大化程度之H2O2，水楊酸，thiourea，GA3，維他命C，氯化鈉，冷卻，及熱處理之先期誘導嘗試揭開生長勢(vigor)提高之生理基礎。大多數之處理誘發瘦果的新合成之胜肽，具低分子量（37kDa: H2O2，水楊酸及氯化鈉處理；57kDa：水楊酸及thiourea處理）及高分子量（157kDa:H2O2，水楊酸，thiourea，GA3，維他命C處理；167kDa：水楊酸處理）；減少溶質漏失；及擴大水溶糖含量。先期誘導縮短了50%發芽之日期，縮短了平均發芽時間(MGT)，改善發芽所需能量(GE)，及最終發芽百分比(FGP)。莖長度可被H2O2，GA3，及氯化鈉先處理所改善；而根長度以氯化鈉及H2O2先處理改善；莖及根之乾重可被H2O2，水楊酸及維他命C先處理改善。GE及FGP都分別與表現之胜肽，水溶糖，莖長，根長，莖重及根重具正相關；而與漏出液之濃度呈負相關。以上之結果綜合顯示：在先處理過之瘦果由於發芽前之代謝潛在改變不但改善發芽過程，而且是長效地改善後來之幼苗生長。在上述許多先處理當中，H2O2，水楊酸，thiourea，及GA3較為有效。綜合言之，先期誘導(priming)之效果在於新胜肽之合成，改善之修補機制，及足夠之發芽基質可供活躍的及更早的幼苗生長。

關鍵字

向日葵 ； 滲出液 ； 幼苗強勢 ； 訊號傳遞 ； 胜肽或蛋白質合成

並列摘要

Seed priming improves vigor, but priming agents may differ greatly in their effectiveness. The present study was performed to unravel the physiological basis of vigor improvement by priming sunflower achenes with pre-optimized levels of hydrogen peroxide (H2O2), salicylic acid (SA), thiourea (TU), gibberellic acid (GA3), ascorbic acid (AA), sodium chloride (NaCl), freezing and heating. Most of the treatments induced de novo synthesis of peptides with low (37 kDa for H2O2, SA and NaCl treatments, and 57 kDa for SA and TU treatments) and high (157 kDa for H2O2, SA, TU, GA3 and AA treatments and 167 kDa for SA treatment) molecular mass, reduced solute leakage, and an enhanced soluble sugar pool in the achenes. Priming reduced days to 50% germination (T50) and mean germination time (MGT) and improved germination energy (GE) and final germination percentage (FGP). Shoot length was improved by priming with H2O2, GA3, and NaCl; root length with NaCl and H2O2; shoot and root dry weight with H2O2, SA and AA. Positive correlations between GE and FGP and expressed peptides, soluble sugars, shoot and root length, and dry weight and negative ones with EC of leachate suggested that pre-germination changes in primed achenes, in addition to improve germination, show lasting effects in promoting seedling growth. Of the treatments, H2O2, SA, TU and GA3 were the most effective. Overall, the effects of priming treatments are related to de novo protein synthesis, an improved repair mechanism, and germination substrates for vigorous and earlier production of seedlings.

並列關鍵字

Leachate ； Protein synthesis ； Seedling vigor ； Signaling ； Sunflower