全國中小學科展

植物學

花容失色-鳳凰花的旗瓣為何會先凋零?

鳳凰木的花朵擁有五片花瓣,上方花瓣與其他紅色花瓣不同,是白色底紅色斑點,根據文獻,這片花瓣稱為旗瓣,功能是作為蜜標來吸引傳粉者。研究觀察發現鳳凰花的旗瓣會先捲曲凋零,和蜜標存在的功能互相矛盾,本組推論與環境、授粉有關連。經研究發現,旗瓣凋零與生長環境、花粉及花蜜是否被採集無關,與授粉方式有關。異株授粉導致旗瓣凋零的時間提前;同株異花授粉旗瓣凋零的時間與自然狀態相近;自花授粉、無授粉則導致旗瓣凋零的時間延後。異株授粉對鳳凰花而言是有效且成功的授粉,會導致旗瓣提早凋零,蜜標隱藏,提高其他尚未有效授粉花朵成功授粉的機會,並且產生成熟的種莢。無效的授粉會導致旗瓣凋零時間延後,藉此等待有效的授粉機會。

探討濕地耐鹽菌對植物耐鹽及根部的交互作用

本研究從濕地篩選出可能為新種的耐鹽菌Oceanobacillus sp.,暫命名為OC2,其在無植物相伴狀態下不會降低土壤含鹽量,但卻在與植物共存後誘發特殊機轉,促使土壤含鹽量降低約,並提升植物耐鹽能力,顯示 OC2與植物存在特殊交互作用。深入研究發現,OC2能產生IAA,並吸引植物根部向其生長以利其進入根部,並在鹽逆境下分泌代謝物以刺激植物合成脯胺酸 (增加達98.5%)提升根部滲透壓、增加葉片類胡蘿蔔素及類黃酮含量以提升植物抗氧化力。植物方面,鹽逆境下植物分泌的化學物質會觸發OC2產生更多的IAA(約17%),藉以刺激植物根系發展以利水分吸收,而OC2的存在會促進根部澱粉酶活性上升達88%,以分解澱粉產生可溶性醣類供OC2使用,推測兩者存在共生關係。本研究展示新種耐鹽菌與植物的交互作用,期待透過此菌改善鹽化農地並能提升作物產量。

羽轉綠肥-自製肥料對蔬果生長的影響

羽毛廢棄物是畜產類廢棄物排名第二大宗,為了提高廢棄羽毛的實用價值與效益,我們利用啤酒酵母菌進行雞羽毛分解。經啤酒酵母分解一個月後的雞毛液肥,含有胺基酸濃度約為0.17 M,是市售肥組的5.67倍。以雞毛液肥灌溉高經濟價值的彩椒及福山萵苣,彩椒果實總質量比市售肥組高出84.6%,果實中含有葡萄糖濃度為23.8%,比市售肥組多出49.7%。碘量法的抗氧化能力試驗中,發現雞毛液肥灌溉的彩椒抗氧化能力比市售肥組高出91.3 %。清除DPPH自由基的能力實驗中,雞毛液肥組的彩椒果實汁液清除自由基能力約是市售肥組的2.82倍。雞毛液肥灌溉的福山萵苣的葉片總質量比市售肥組多出116.2%。可以發現啤酒酵母分解的雞毛液肥,確實可取代市售肥料,當作彩椒及福山萵苣的養分。希望藉此研究能將廢棄雞毛再利用,減少環境負擔,讓農業永續發展。

Exploiting the beneficial role of Biochar and Titanium (Ti) as a Sustainable and Green Strategy for Improving Agricultural Output in Saudi Arabia: Wheat as an Using Wheat as a Model

The present research work aimed to assess the impact of biochar (BC) amendment (5%) and foliar supplementation of titanium (Ti) at a concentration of 50 mg L-1 TiO2 on the growth, chlorophyll content, and biochemical parameters of wheat (Triticum aestivum L). The results demonstrated significant improvements in several aspects of wheat physiology due to these treatments, both individually and in combination. Plant height, as well as fresh and dry weight of wheat, exhibited substantial increases when subjected to Ti and BC treatments, with the highest enhancements observed in plants treated with both Ti and BC. Furthermore, chlorophyll content, including chlorophyll a, chlorophyll b, total chlorophylls, and carotenoids, showed marked increases in response to individual Ti and BC treatments, with even greater improvements when both treatments were combined. In terms of biochemical parameters, the content of proline, sugars, and free amino acids significantly increased in plants grown in soils amended with BC. Additionally, foliar Ti treatment led to elevated levels of these biochemical constituents. The combined treatment of Ti and BC resulted in the most pronounced effects. Moreover, oxidative damage parameters, such as hydrogen peroxide, lipid peroxide, and electrolyte leakage, were notably reduced in plants subjected to Ti and BC treatments, either individually or together. The activity of antioxidant enzymes, including superoxide dismutase, catalase, and ascorbate peroxidase, exhibited significant increases in response to Ti and BC treatments, further emphasizing their beneficial effects on wheat plants. Overall, this investigation shows that biochar amendment and titanium foliar supplementation both have beneficial effects on wheat development and biochemical parameters; these findings may be relevant to efforts to increase crop productivity and stress tolerance.

熱不倒的番茄—耐熱細菌對番茄根莖之研究

本次實驗以地熱溫泉區的土壤中所篩選出的8隻耐熱菌種,並加以純化、液態培養,將8種菌液稀釋成度三種不同濃度(100X、200X、500X),以恆溫培養箱控制環境溫度(25℃、30℃、35℃)模擬環境變因,並測試和定量菌株的溶磷、固氮能力,亦測試載鐵、抗番茄萎凋菌能力及對於聖女番茄及桃紅番茄所帶來的影響。本研究發現 LC26 及 LC28 可於熱逆境下顯著促進聖女番茄生長,此外LC03亦能於熱逆境下明顯促進桃紅番茄生長。本研究也發現LC03、LC26及LC28對玉米及胡蘿蔔有最好的促進生長效果,而對青江菜有最明顯的抑制生長效果,可作為輪耕作物之參考。最後本研究發現這三隻菌種皆對大花咸豐草之生長有抑制情形,其中以LC26(500X)抑制效果最佳。

高山生態群聚植物集中開花與昆蟲交互作用網絡之研究

本研究首度以植物學、花粉學、昆蟲學及生態統計學探討臺灣高山傳粉生態網絡。花季中期以蜂類為主,後期為蠅類。昆蟲及植物交互網絡緊密連結無子群體,仰賴優勢物種支撐。蜂期為高山薔薇、玉山櫻草、貓兒菊、信義雄蜂;蠅期為一枝黃花、貓兒菊、家蠅。此兩期昆蟲與植物的穩健性不足,蠅期更易崩解。蜂類訪花具多樣性,蠅類訪花較專一。因蜂類、蠅類習性與身體特徵不相同,蠅類對花展幅 (Visit Unit)大、花冠筒淺、花冠筒筒徑小、還原糖含量高、花粉及花蜜之間的距離大、柱頭面積小的植物較能專一攜帶其花粉。共用傳粉者帶來異種花粉,以GLMM分析同異種花粉數量變化關係,發現一起開花略助於授粉。貓兒菊已入侵成為優勢物種,花粉汙染90%的物種,必須移除。

麩醯胺酸誘導阿拉伯芥的受體表現

自然界中,植物以NO₃⁻和NH4+作為主要氮源,在吸收後轉化為麩胺酸(Glu)和麩醯胺酸(Gln)作為第一產物進行基本生理反應,在我們實驗室先前的研究中,發現Gln會誘導阿拉伯芥側根生長、壓力反應和抗病性,所以提出了一種假說「細胞外的Gln是營養氮源,也是一種“危險訊號”」,藉由可能存在的Gln的受體表現。目前我進行了其中三組受體的測試,分別是wall-associated kinase2(WAK2)、wall-associated kinase3(WAK3)和EF-Tu受體(EFR),WAK家族是穩定細胞壁果膠的受體激酶,然而我們實驗中發現WAK3在wak3 muntant的表現是不穩定的。EFR為接收EF-Tu(elongation factor thermal unstable)的模式辨識受體(PRR),參與活化植物防禦及PAMP-triggered immunity (PTI),efr muntant在Gln的誘導下表現了防禦相關基因與水楊酸生成之相關基因。本研究將有助於深入理解Gln在植物防禦和側根生長中的功能及其調控機制,並為未來的作物改良和病害防治提供理論基礎。

熱不倒的番茄—耐熱細菌對番茄根莖之研究

本次實驗以地熱溫泉區的土壤中所篩選出的8隻耐熱菌種,並加以純化、液態培養,將8種菌液稀釋成度三種不同濃度(100X、200X、500X),以恆溫培養箱控制環境溫度(25℃、30℃、35℃)模擬環境變因,並測試和定量菌株的溶磷、固氮能力,亦測試載鐵、抗番茄萎凋菌能力及對於聖女番茄及桃紅番茄所帶來的影響。本研究發現 LC26 及 LC28 可於熱逆境下顯著促進聖女番茄生長,此外LC03亦能於熱逆境下明顯促進桃紅番茄生長。本研究也發現LC03、LC26及LC28對玉米及胡蘿蔔有最好的促進生長效果,而對青江菜有最明顯的抑制生長效果,可作為輪耕作物之參考。最後本研究發現這三隻菌種皆對大花咸豐草之生長有抑制情形,其中以LC26(500X)抑制效果最佳。

Decoding Climate Resilience: Functional Profiling of Protein Phosphatase 2C Family Genes for Abiotic Stress Tolerance in Rice

Problem • Rice is the primary cereal crop consumed by nearly half the population worldwide • By 2050, there will be a 50% increase in demand for rice • The world’s poor populations depend more on rice, both for income and consumption, than any other food. Rice is the single-largest source of employment and income for rural people • Worldwide, 51–82% of agricultural crop yield is lost annually due to abiotic stress due to climate change • Climate change causes extreme temperatures, erratic rainfall, dangerous droughts, and increased salinity from rising sea levels Solution • To adapt to abiotic stress, rice has intricate signaling pathways, particularly those mediated by the phytohormone abscisic acid (ABA), that cause an increase in stress tolerance • Clade A genes of the Protein Phosphatase 2C (PP2C) gene family are known to be negative regulators of the ABA signaling pathway. • “Deleting” these genes activates the ABA pathway and increases stress tolerance in rice without inducing stress CRISPR gene editing technology is the ideal solution Research Goal • While the role of PP2C genes in stress response is recognized, there is a gap in understanding the specific genes within this family that contribute significantly to stress signaling. Furthermore, there is a need for a detailed investigation into the effects of targeted CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) genome editing on rice stress response pathways.

探討候選基因對角質層與氣孔發育的調控之影響

植物進化成陸生植物的過程中,氣孔和角質層是關鍵特徵。氣孔由保衛細胞調控,負責二氧化碳進入和水分蒸發;角質層則保護植物免受水分流失及環境壓力。調控這些特徵的基因尚不明確。本研究利用全基因組關聯分析(GWAS)探討阿拉伯芥的角質層和氣孔發育。GWAS結果顯示,與角質層厚度相關的基因位於第二條染色體,而與二氧化碳吸收效率相關的基因位於第五條染色體。氣孔導度和水分吸收效率的調控基因可能在第一、三、四條染色體上。角質層變薄時,氣孔密度下降,導致氣孔導度和水分蒸散率上升;而當角質層通透性增加到一定程度時,二氧化碳固定效率達飽和。此外,透過反向遺傳學篩選候選基因,研究特定基因對角質層合成及光合作用效率的影響。突變株分析顯示,抑制控制角質層或氣孔的基因會促進另一性狀的表現,未來可進一步探討自然族群中相關基因的功能。