Ekspresi Gen Trypsin Inhibitor Sengon (Falcataria moluccana Miq.) yang Sehat dan Terserang Hama Boktor

Abstract

Sengon (Falcataria moluccana Miq.) merupakan salah satu jenis cepat tumbuh yang kayunya banyak dimanfaatkan sehingga sering dibudidayakan terutama di Pulau Jawa. Adanya serangan hama penggerek batang boktor (Xystrocera festiva Thombs) terhadap sengon menyebabkan kerugian yang besar karena dapat menurunkan kualitas kayu dan menurunkan nilai jual kayu sengon. Secara alami tanaman sengon memiliki gen ketahanan terhadap serangan hama boktor, salah satunya adalah trypsin inhibitor. Tujuan penelitian ini adalah membandingkan tingkat ekspresi gen trypsin inhibitor pada kambium pohon sengon resisten dan terserang hama boktor secara kuantitatif dengan teknik Quantitative Real Time PCR. Gen target yang digunakan yaitu trypsin inhibitor (TI) dan gen Actin sebagai internal kontrol dirancang dari analisa data transkriptom sengon. Data Threshold cycle (CT) yang diperoleh kemudian dikuantifikasi menggunakan metode comparative CT method (2 -ΔΔCT). Hasil kuantifikasi menunjukkan tingkat ekspresi gen trypsin inhibitor pada ketiga sampel sengon resisten yaitu sebesar 1.90, 2.20, dan 2,85 sedangkan sengon terserang boktor sebesar 4.07, 2.05, dan 4.08. Rata-rata ekspresi gen trypsin inhibitor pada sengon terserang hama boktor lebih tinggi dibandingkan sengon yang resisten. Kata kunci: Falcataria moluccana, Trypsin Inhibitor, Quantitative Real Time PCR

Sengon (Falcataria moluccana Miq.) is highly demanded fast growing tree species which leads to the increasing sengon cultivation especially in Java. Boktor pest (Xystrocera festiva Thombs) decrease the quality of sengon wood, causing a high loss due to lower selling price of the log. Naturally sengon has resistance gene to defend itself from boktor pest attacks, and one of these genes is trypsin inhibitor. This study aimed to comparing the level of trypsin inhibitor gene expression in sengon’s cambium that is resistant and attacked by boktor pests. The analysis of gene expression level was carried out using the Real Time PCR technique. Primers of trypsin inhibitor (TI) gene as the target gene and Actin gene as the internal control were designed from sengon’s transcriptomic data analysis. Threshold cycle (CT) that obtained then quantified using comparative CT method (2 -ΔΔCT). Quantification results showed that the expression level of trypsin inhibitor from three resistant samples are 1.90, 2.20, and 2,85 while in sengon attacked by boktor are 4.07, 2.05, and 4,08. The average trypsin inhibitor gene expression in sengon attacked by boktor pest was higher than resistant ones. Keywords: Falcataria moluccana, Trypsin Inhibitor, Quantitative Real Time PCR